1
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Li D, Radhakrishnan R, Akopian N. Location Qubits in a Multiple-Quantum-Dot System. NANO LETTERS 2024; 24:5656-5661. [PMID: 38657275 DOI: 10.1021/acs.nanolett.4c01272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
A physical platform for nodes of the envisioned quantum Internet is long-sought. Here we propose such a platform, along with a conceptually simple and experimentally uncomplicated quantum information processing scheme, realized in a system of multiple crystal-phase quantum dots. We introduce novel location qubits, describe a method to construct a universal set of all-optical quantum gates, and simulate their performance in realistic structures, including decoherence sources. Our results show that location qubits are robust against the main decoherence mechanisms, and realistic single-qubit gate fidelities exceed 99.9%. Our scheme paves a clear way toward constructing multiqubit solid-state quantum registers with a built-in photonic interface─a key building block of the forthcoming quantum Internet.
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Affiliation(s)
- Dayang Li
- DTU Department of Electrical and Photonics Engineering, Technical University of Denmark, Ørsteds Plads Building 343, 2800 Kongens Lyngby, Denmark
| | - Rohan Radhakrishnan
- DTU Department of Electrical and Photonics Engineering, Technical University of Denmark, Ørsteds Plads Building 343, 2800 Kongens Lyngby, Denmark
| | - Nika Akopian
- DTU Department of Electrical and Photonics Engineering, Technical University of Denmark, Ørsteds Plads Building 343, 2800 Kongens Lyngby, Denmark
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2
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Liu R, Tang B, Fan F. Enhanced Spin Polarization from Biaxially Strained Colloidal Quantum Dots. J Phys Chem Lett 2024; 15:869-873. [PMID: 38237051 DOI: 10.1021/acs.jpclett.3c03495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2024]
Abstract
Electron and hole spin polarization is crucial for quantum dots to be used in spin lasers and quantum information processing. However, the degree of spin polarization in II-VI and III-V semiconductor quantum dots is low because of the degenerated valence band. Here, we increase the light and heavy hole degeneracy by introducing biaxial strain into CdSe-based quantum dots, enabling the degree of spin polarization to be increased from 20% to 50% under photoexcitation. The optical gain threshold measurement further reveals that the increase in polarization helps to reduce the gain threshold.
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Affiliation(s)
- Ruixiang Liu
- CAS Key Laboratory of Microscale Magnetic Resonance and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Beibei Tang
- CAS Key Laboratory of Microscale Magnetic Resonance and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Fengjia Fan
- CAS Key Laboratory of Microscale Magnetic Resonance and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
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3
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Mehdi E, Gundín M, Millet C, Somaschi N, Lemaître A, Sagnes I, Le Gratiet L, Fioretto DA, Belabas N, Krebs O, Senellart P, Lanco L. Giant optical polarisation rotations induced by a single quantum dot spin. Nat Commun 2024; 15:598. [PMID: 38238312 PMCID: PMC10796934 DOI: 10.1038/s41467-023-44651-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 12/27/2023] [Indexed: 01/22/2024] Open
Abstract
In the framework of optical quantum computing and communications, a major objective consists in building receiving nodes implementing conditional operations on incoming photons, using a single stationary qubit. In particular, the quest for scalable nodes motivated the development of cavity-enhanced spin-photon interfaces with solid-state emitters. An important challenge remains, however, to produce a stable, controllable, spin-dependent photon state, in a deterministic way. Here we use an electrically-contacted pillar-based cavity, embedding a single InGaAs quantum dot, to demonstrate giant polarisation rotations induced on reflected photons by a single electron spin. A complete tomography approach is introduced to extrapolate the output polarisation Stokes vector, conditioned by a specific spin state, in presence of spin and charge fluctuations. We experimentally approach polarisation states conditionally rotated by [Formula: see text], π, and [Formula: see text] in the Poincaré sphere with extrapolated fidelities of (97 ± 1) %, (84 ± 7) %, and (90 ± 8) %, respectively. We find that an enhanced light-matter coupling, together with limited cavity birefringence and reduced spectral fluctuations, allow targeting most conditional rotations in the Poincaré sphere, with a control both in longitude and latitude. Such polarisation control may prove crucial to adapt spin-photon interfaces to various configurations and protocols for quantum information.
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Affiliation(s)
- E Mehdi
- Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies, 91120, Palaiseau, France
- Université Paris Cité, Centre de Nanosciences et de Nanotechnologies, 91120, Palaiseau, France
| | - M Gundín
- Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies, 91120, Palaiseau, France
| | - C Millet
- Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies, 91120, Palaiseau, France
| | - N Somaschi
- Quandela, 7 rue Leonard de Vinci, 91300, Massy, France
| | - A Lemaître
- Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies, 91120, Palaiseau, France
| | - I Sagnes
- Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies, 91120, Palaiseau, France
| | - L Le Gratiet
- Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies, 91120, Palaiseau, France
| | - D A Fioretto
- Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies, 91120, Palaiseau, France
- Quandela, 7 rue Leonard de Vinci, 91300, Massy, France
| | - N Belabas
- Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies, 91120, Palaiseau, France
| | - O Krebs
- Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies, 91120, Palaiseau, France
| | - P Senellart
- Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies, 91120, Palaiseau, France
| | - L Lanco
- Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies, 91120, Palaiseau, France.
- Université Paris Cité, Centre de Nanosciences et de Nanotechnologies, 91120, Palaiseau, France.
- Institut Universitaire de France (IUF), 75005, Paris, France.
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4
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Shibata K, Yoshida M, Hirakawa K, Otsuka T, Bisri SZ, Iwasa Y. Single PbS colloidal quantum dot transistors. Nat Commun 2023; 14:7486. [PMID: 37980351 PMCID: PMC10657373 DOI: 10.1038/s41467-023-43343-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 11/07/2023] [Indexed: 11/20/2023] Open
Abstract
Colloidal quantum dots are sub-10 nm semiconductors treated with liquid processes, rendering them attractive candidates for single-electron transistors operating at high temperatures. However, there have been few reports on single-electron transistors using colloidal quantum dots due to the difficulty in fabrication. In this work, we fabricated single-electron transistors using single oleic acid-capped PbS quantum dot coupled to nanogap metal electrodes and measured single-electron tunneling. We observed dot size-dependent carrier transport, orbital-dependent electron charging energy and conductance, electric field modulation of the electron confinement potential, and the Kondo effect, which provide nanoscopic insights into carrier transport through single colloidal quantum dots. Moreover, the large charging energy in small quantum dots enables single-electron transistor operation even at room temperature. These findings, as well as the commercial availability and high stability, make PbS quantum dots promising for the development of quantum information and optoelectronic devices, particularly room-temperature single-electron transistors with excellent optical properties.
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Affiliation(s)
- Kenji Shibata
- Department of Electrical and Electronic Engineering, Tohoku Institute of Technology, 35-1 Yagiyama, Kasumi-cho, Taihaku-ku, Sendai, 982-8577, Japan.
| | - Masaki Yoshida
- Department of Electrical and Electronic Engineering, Tohoku Institute of Technology, 35-1 Yagiyama, Kasumi-cho, Taihaku-ku, Sendai, 982-8577, Japan
| | - Kazuhiko Hirakawa
- Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505, Japan
- Institute for Nano Quantum Information Electronics, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505, Japan
| | - Tomohiro Otsuka
- Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
- WPI Advanced Institute for Materials Research, Tohoku University, Sendai, 980-8577, Japan
- Department of Electronic Engineering, Tohoku University, Aoba 6-6-05, Aramaki, Aoba-Ku, Sendai, 980-8579, Japan
- Center for Science and Innovation in Spintronics, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
- Quantum Functional System Research Group, RIKEN Center for Emergent Matter Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Satria Zulkarnaen Bisri
- Emergent Device Research Team, RIKEN Center for Emergent Matter Science, 2-1 Hirosawa Wako, Saitama, 351-0198, Japan
- Department of Applied Physics and Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei-shi, Tokyo, 184-8588, Japan
| | - Yoshihiro Iwasa
- Emergent Device Research Team, RIKEN Center for Emergent Matter Science, 2-1 Hirosawa Wako, Saitama, 351-0198, Japan
- Department of Applied Physics and Quantum-Phase Electronics Center, University of Tokyo, Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
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5
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Tiranov A, Angelopoulou V, van Diepen CJ, Schrinski B, Sandberg OAD, Wang Y, Midolo L, Scholz S, Wieck AD, Ludwig A, Sørensen AS, Lodahl P. Collective super- and subradiant dynamics between distant optical quantum emitters. Science 2023; 379:389-393. [PMID: 36701463 DOI: 10.1126/science.ade9324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Photon emission is the hallmark of light-matter interaction and the foundation of photonic quantum science, enabling advanced sources for quantum communication and computing. Although single-emitter radiation can be tailored by the photonic environment, the introduction of multiple emitters extends this picture. A fundamental challenge, however, is that the radiative dipole-dipole coupling rapidly decays with spatial separation, typically within a fraction of the optical wavelength. We realize distant dipole-dipole radiative coupling with pairs of solid-state optical quantum emitters embedded in a nanophotonic waveguide. We dynamically probe the collective response and identify both super- and subradiant emission as well as means to control the dynamics by proper excitation techniques. Our work constitutes a foundational step toward multiemitter applications for scalable quantum-information processing.
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Affiliation(s)
- Alexey Tiranov
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | - Vasiliki Angelopoulou
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | - Cornelis Jacobus van Diepen
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | - Björn Schrinski
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | | | - Ying Wang
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | - Leonardo Midolo
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | - Sven Scholz
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraß e 150, D-44801 Bochum, Germany
| | - Andreas Dirk Wieck
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraß e 150, D-44801 Bochum, Germany
| | - Arne Ludwig
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraß e 150, D-44801 Bochum, Germany
| | - Anders Søndberg Sørensen
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | - Peter Lodahl
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
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6
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Nguyen HA, Sharp D, Fröch JE, Cai YY, Wu S, Monahan M, Munley C, Manna A, Majumdar A, Kagan CR, Cossairt BM. Deterministic Quantum Light Arrays from Giant Silica-Shelled Quantum Dots. ACS APPLIED MATERIALS & INTERFACES 2023; 15:4294-4302. [PMID: 36507852 DOI: 10.1021/acsami.2c18475] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Colloidal quantum dots (QDs) are promising candidates for single-photon sources with applications in photonic quantum information technologies. Developing practical photonic quantum devices with colloidal materials, however, requires scalable deterministic placement of stable single QD emitters. In this work, we describe a method to exploit QD size to facilitate deterministic positioning of single QDs into large arrays while maintaining their photostability and single-photon emission properties. CdSe/CdS core/shell QDs were encapsulated in silica to both increase their physical size without perturbing their quantum-confined emission and enhance their photostability. These giant QDs were then precisely positioned into ordered arrays using template-assisted self-assembly with a 75% yield for single QDs. We show that the QDs before and after assembly exhibit antibunching behavior at room temperature and their optical properties are retained after an extended period of time. Together, this bottom-up synthetic approach via silica shelling and the robust template-assisted self-assembly offer a unique strategy to produce scalable quantum photonics platforms using colloidal QDs as single-photon emitters.
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Affiliation(s)
- Hao A Nguyen
- Department of Chemistry, University of Washington, Seattle, Washington 98189, United States
| | - David Sharp
- Department of Physics, University of Washington, Seattle, Washington 98185, United States
| | - Johannes E Fröch
- Department of Physics, University of Washington, Seattle, Washington 98185, United States
- Department of Electrical and Computer Engineering, University of Washington, Seattle, Washington 98195, United States
| | - Yi-Yu Cai
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Shenwei Wu
- Department of Chemistry, University of Washington, Seattle, Washington 98189, United States
| | - Madison Monahan
- Department of Chemistry, University of Washington, Seattle, Washington 98189, United States
| | - Christopher Munley
- Department of Physics, University of Washington, Seattle, Washington 98185, United States
| | - Arnab Manna
- Department of Physics, University of Washington, Seattle, Washington 98185, United States
| | - Arka Majumdar
- Department of Physics, University of Washington, Seattle, Washington 98185, United States
- Department of Electrical and Computer Engineering, University of Washington, Seattle, Washington 98195, United States
| | - Cherie R Kagan
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Brandi M Cossairt
- Department of Chemistry, University of Washington, Seattle, Washington 98189, United States
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7
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Preuß JA, Gehring H, Schmidt R, Jin L, Wendland D, Kern J, Pernice WHP, de Vasconcellos SM, Bratschitsch R. Low-Divergence hBN Single-Photon Source with a 3D-Printed Low-Fluorescence Elliptical Polymer Microlens. NANO LETTERS 2023; 23:407-413. [PMID: 36445803 DOI: 10.1021/acs.nanolett.2c03001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Efficiently collecting light from single-photon emitters is crucial for photonic quantum technologies. Here, we develop and use an ultralow fluorescence photopolymer to three-dimensionally print micrometer-sized elliptical lenses on individual precharacterized single-photon emitters in hexagonal boron nitride (hBN) nanocrystals, operating in the visible regime. The elliptical lens design beams the light highly efficiently into the far field, rendering bulky objective lenses obsolete. Using back focal plane imaging, we confirm that the emission is collimated to a narrow low-divergence beam with a half width at half-maximum of 2.2°. Using photon correlation measurements, we demonstrate that the single-photon character remains undisturbed by the polymer lens. The strongly directed emission and increased collection efficiency is highly beneficial for quantum optical experiments. Furthermore, our approach paves the way for a highly parallel fiber-based detection of single photons from hBN nanocrystals.
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Affiliation(s)
- Johann A Preuß
- Institute of Physics and Center for Nanotechnology, University of Münster, Wilhelm-Klemm-Str. 10, 48149 Münster, Germany
| | - Helge Gehring
- Institute of Physics and Center for Nanotechnology, University of Münster, Wilhelm-Klemm-Str. 10, 48149 Münster, Germany
- Center for Soft Nanoscience, University of Münster, Heisenbergstr. 11, 48149 Münster, Germany
| | - Robert Schmidt
- Institute of Physics and Center for Nanotechnology, University of Münster, Wilhelm-Klemm-Str. 10, 48149 Münster, Germany
| | - Lin Jin
- Institute of Physics and Center for Nanotechnology, University of Münster, Wilhelm-Klemm-Str. 10, 48149 Münster, Germany
- Center for Soft Nanoscience, University of Münster, Heisenbergstr. 11, 48149 Münster, Germany
| | - Daniel Wendland
- Institute of Physics and Center for Nanotechnology, University of Münster, Wilhelm-Klemm-Str. 10, 48149 Münster, Germany
- Center for Soft Nanoscience, University of Münster, Heisenbergstr. 11, 48149 Münster, Germany
| | - Johannes Kern
- Institute of Physics and Center for Nanotechnology, University of Münster, Wilhelm-Klemm-Str. 10, 48149 Münster, Germany
| | - Wolfram H P Pernice
- Institute of Physics and Center for Nanotechnology, University of Münster, Wilhelm-Klemm-Str. 10, 48149 Münster, Germany
- Center for Soft Nanoscience, University of Münster, Heisenbergstr. 11, 48149 Münster, Germany
- Kirchhoff-Institute for Physics, University of Heidelberg, Im Neuenheimer Feld 227, 69120 Heidelberg, Germany
| | - Steffen Michaelis de Vasconcellos
- Institute of Physics and Center for Nanotechnology, University of Münster, Wilhelm-Klemm-Str. 10, 48149 Münster, Germany
- Department of Physics, TU Dortmund University, Otto-Hahn-Str. 4, 44227 Dortmund, Germany
| | - Rudolf Bratschitsch
- Institute of Physics and Center for Nanotechnology, University of Münster, Wilhelm-Klemm-Str. 10, 48149 Münster, Germany
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8
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Singh H, Farfurnik D, Luo Z, Bracker AS, Carter SG, Waks E. Optical Transparency Induced by a Largely Purcell Enhanced Quantum Dot in a Polarization-Degenerate Cavity. NANO LETTERS 2022; 22:7959-7964. [PMID: 36129824 DOI: 10.1021/acs.nanolett.2c03098] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Optically active spin systems coupled to photonic cavities with high cooperativity can generate strong light-matter interactions, a key ingredient in quantum networks. However, obtaining high cooperativities for quantum information processing often involves the use of photonic crystal cavities that feature a poor optical access from the free space, especially to circularly polarized light required for the coherent control of the spin. Here, we demonstrate coupling with a cooperativity as high as 8 of an InAs/GaAs quantum dot to a fabricated bullseye cavity that provides nearly degenerate and Gaussian polarization modes for efficient optical accessing. We observe spontaneous emission lifetimes of the quantum dot as short as 80 ps (an ∼15 Purcell enhancement) and a ∼80% transparency of light reflected from the cavity. Leveraging the induced transparency for photon switching while coherently controlling the quantum dot spin could contribute to ongoing efforts of establishing quantum networks.
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Affiliation(s)
- Harjot Singh
- Department of Electrical and Computer Engineering, Institute for Research in Electronics and Applied Physics, and Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, United States
| | - Demitry Farfurnik
- Department of Electrical and Computer Engineering, Institute for Research in Electronics and Applied Physics, and Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, United States
| | - Zhouchen Luo
- Department of Electrical and Computer Engineering, Institute for Research in Electronics and Applied Physics, and Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, United States
| | - Allan S Bracker
- Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, D.C. 20375, United States
| | - Samuel G Carter
- Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, D.C. 20375, United States
| | - Edo Waks
- Department of Electrical and Computer Engineering, Institute for Research in Electronics and Applied Physics, and Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, United States
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9
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Bosco S, Scarlino P, Klinovaja J, Loss D. Fully Tunable Longitudinal Spin-Photon Interactions in Si and Ge Quantum Dots. PHYSICAL REVIEW LETTERS 2022; 129:066801. [PMID: 36018647 DOI: 10.1103/physrevlett.129.066801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 07/06/2022] [Indexed: 06/15/2023]
Abstract
Spin qubits in silicon and germanium quantum dots are promising platforms for quantum computing, but entangling spin qubits over micrometer distances remains a critical challenge. Current prototypical architectures maximize transversal interactions between qubits and microwave resonators, where the spin state is flipped by nearly resonant photons. However, these interactions cause backaction on the qubit that yields unavoidable residual qubit-qubit couplings and significantly affects the gate fidelity. Strikingly, residual couplings vanish when spin-photon interactions are longitudinal and photons couple to the phase of the qubit. We show that large and tunable spin-photon interactions emerge naturally in state-of-the-art hole spin qubits and that they change from transversal to longitudinal depending on the magnetic field direction. We propose ways to electrically control and measure these interactions, as well as realistic protocols to implement fast high-fidelity two-qubit entangling gates. These protocols work also at high temperatures, paving the way toward the implementation of large-scale quantum processors.
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Affiliation(s)
- Stefano Bosco
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - Pasquale Scarlino
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Jelena Klinovaja
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - Daniel Loss
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
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10
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Zhai L, Nguyen GN, Spinnler C, Ritzmann J, Löbl MC, Wieck AD, Ludwig A, Javadi A, Warburton RJ. Quantum interference of identical photons from remote GaAs quantum dots. NATURE NANOTECHNOLOGY 2022; 17:829-833. [PMID: 35589820 DOI: 10.1038/s41565-022-01131-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 04/01/2022] [Indexed: 06/15/2023]
Abstract
Photonic quantum technology provides a viable route to quantum communication1,2, quantum simulation3 and quantum information processing4. Recent progress has seen the realization of boson sampling using 20 single photons3 and quantum key distribution over hundreds of kilometres2. Scaling the complexity requires architectures containing multiple photon sources, photon counters and a large number of indistinguishable single photons. Semiconductor quantum dots are bright and fast sources of coherent single photons5-9. For applications, a roadblock is the poor quantum coherence on interfering single photons created by independent quantum dots10,11. Here we demonstrate two-photon interference with near-unity visibility (93.0 ± 0.8)% using photons from two completely separate GaAs quantum dots. The experiment retains all the emission into the zero phonon line-only the weak phonon sideband is rejected; temporal post-selection is not employed. By exploiting quantum interference, we demonstrate a photonic controlled-not circuit and an entanglement with fidelity of (85.0 ± 1.0)% between photons of different origins. The two-photon interference visibility is high enough that the entanglement fidelity is well above the classical threshold. The high mutual coherence of the photons stems from high-quality materials, diode structure and relatively large quantum dot size. Our results establish a platform-GaAs quantum dots-for creating coherent single photons in a scalable way.
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Affiliation(s)
- Liang Zhai
- Department of Physics, University of Basel, Basel, Switzerland.
| | - Giang N Nguyen
- Department of Physics, University of Basel, Basel, Switzerland
| | | | - Julian Ritzmann
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Bochum, Germany
| | - Matthias C Löbl
- Department of Physics, University of Basel, Basel, Switzerland
| | - Andreas D Wieck
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Bochum, Germany
| | - Arne Ludwig
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Bochum, Germany
| | - Alisa Javadi
- Department of Physics, University of Basel, Basel, Switzerland
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11
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Tran KX, Bracker AS, Yakes MK, Grim JQ, Carter SG. Enhanced Spin Coherence of a Self-Assembled Quantum Dot Molecule at the Optimal Electrical Bias. PHYSICAL REVIEW LETTERS 2022; 129:027403. [PMID: 35867431 DOI: 10.1103/physrevlett.129.027403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 05/27/2022] [Indexed: 06/15/2023]
Abstract
A pair of coupled dots with one electron in each dot can provide improvements in spin coherence, particularly at an electrical bias called the "sweet spot," but few measurements have been performed on self-assembled dots in this regime. Here, we directly measure the T_{2}^{*} coherence time of the singlet-triplet states in this system as a function of bias and magnetic field, obtaining a maximum T_{2}^{*} of 60 ns, more than an order of magnitude higher than an electron spin in a single quantum dot. Our results uncover two main dephasing mechanisms: electrical noise away from the sweet spot, and a magnetic field dependent interaction with nuclear spins due to a difference in g factors.
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Affiliation(s)
- Kha X Tran
- Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, D.C. 20375, USA
| | - Allan S Bracker
- Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, D.C. 20375, USA
| | - Michael K Yakes
- Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, D.C. 20375, USA
| | - Joel Q Grim
- Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, D.C. 20375, USA
| | - Samuel G Carter
- Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, D.C. 20375, USA
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12
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Appel MH, Tiranov A, Pabst S, Chan ML, Starup C, Wang Y, Midolo L, Tiurev K, Scholz S, Wieck AD, Ludwig A, Sørensen AS, Lodahl P. Entangling a Hole Spin with a Time-Bin Photon: A Waveguide Approach for Quantum Dot Sources of Multiphoton Entanglement. PHYSICAL REVIEW LETTERS 2022; 128:233602. [PMID: 35749189 DOI: 10.1103/physrevlett.128.233602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 03/13/2022] [Accepted: 04/06/2022] [Indexed: 06/15/2023]
Abstract
Deterministic sources of multiphoton entanglement are highly attractive for quantum information processing but are challenging to realize experimentally. In this Letter, we demonstrate a route toward a scaleable source of time-bin encoded Greenberger-Horne-Zeilinger and linear cluster states from a solid-state quantum dot embedded in a nanophotonic crystal waveguide. By utilizing a self-stabilizing double-pass interferometer, we measure a spin-photon Bell state with (67.8±0.4)% fidelity and devise steps for significant further improvements. By employing strict resonant excitation, we demonstrate a photon indistinguishability of (95.7±0.8)%, which is conducive to fusion of multiple cluster states for scaling up the technology and producing more general graph states.
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Affiliation(s)
- Martin Hayhurst Appel
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | - Alexey Tiranov
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | - Simon Pabst
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | - Ming Lai Chan
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | - Christian Starup
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | - Ying Wang
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | - Leonardo Midolo
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | - Konstantin Tiurev
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | - Sven Scholz
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraße 150, 44801 Bochum, Germany
| | - Andreas D Wieck
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraße 150, 44801 Bochum, Germany
| | - Arne Ludwig
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraße 150, 44801 Bochum, Germany
| | - Anders Søndberg Sørensen
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | - Peter Lodahl
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
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13
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Chang TY, Kim H, Hubbard WA, Azizur-Rahman KM, Ju JJ, Kim JH, Lee WJ, Huffaker D. InAsP Quantum Dot-Embedded InP Nanowires toward Silicon Photonic Applications. ACS APPLIED MATERIALS & INTERFACES 2022; 14:12488-12494. [PMID: 35175722 DOI: 10.1021/acsami.1c21013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Quantum dot (QD) emitters on silicon platforms have been considered as a fascinating approach to building next-generation quantum light sources toward unbreakable secure communications. However, it has been challenging to integrate position-controlled QDs operating at the telecom band, which is a crucial requirement for practical applications. Here, we report monolithically integrated InAsP QDs embedded in InP nanowires on silicon. The positions of QD nanowires are predetermined by the lithography of gold catalysts, and the 3D geometry of nanowire heterostructures is precisely controlled. The InAsP QD forms atomically sharp interfaces with surrounding InP nanowires, which is in situ passivated by InP shells. The linewidths of the excitonic (X) and biexcitonic (XX) emissions from the QD and their power-dependent peak intensities reveal that the proposed QD-in-nanowire structure could be utilized as a non-classical light source that operates at silicon-transparent wavelengths, showing a great potential for diverse quantum optical and silicon photonic applications.
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Affiliation(s)
- Ting-Yuan Chang
- Department of Electrical and Computer Engineering, University of California Los Angeles, Los Angeles, California 90095, United States
| | - Hyunseok Kim
- Department of Electrical and Computer Engineering, University of California Los Angeles, Los Angeles, California 90095, United States
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - William A Hubbard
- NanoElectronic Imaging Inc., Los Angeles, California 90095, United States
| | | | - Jung Jin Ju
- Electronics and Telecommunications Research Institute, Daejeon 34129, South Korea
| | - Je-Hyung Kim
- Department of Physics, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, South Korea
| | - Wook-Jae Lee
- Electronics and Telecommunications Research Institute, Daejeon 34129, South Korea
- Department of Data Information and Physics, Kongju National University, Gongju 32588, South Korea
| | - Diana Huffaker
- Department of Electrical and Computer Engineering, University of California Los Angeles, Los Angeles, California 90095, United States
- School of Physics and Astronomy, Cardiff University, Cardiff, Wales CF24 3AA, U.K
- Department of Electrical Engineering, University of Texas at Arlington, Arlington, Texas 76019, United States
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14
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Bosco S, Loss D. Fully Tunable Hyperfine Interactions of Hole Spin Qubits in Si and Ge Quantum Dots. PHYSICAL REVIEW LETTERS 2021; 127:190501. [PMID: 34797148 DOI: 10.1103/physrevlett.127.190501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 10/13/2021] [Indexed: 06/13/2023]
Abstract
Hole spin qubits are frontrunner platforms for scalable quantum computers, but state-of-the-art devices suffer from noise originating from the hyperfine interactions with nuclear defects. We show that these interactions have a highly tunable anisotropy that is controlled by device design and external electric fields. This tunability enables sweet spots where the hyperfine noise is suppressed by an order of magnitude and is comparable to isotopically purified materials. We identify surprisingly simple designs where the qubits are highly coherent and are largely unaffected by both charge and hyperfine noise. We find that the large spin-orbit interaction typical of elongated quantum dots not only speeds up qubit operations, but also dramatically renormalizes the hyperfine noise, altering qualitatively the dynamics of driven qubits and enhancing the fidelity of qubit gates. Our findings serve as guidelines to design high performance qubits for scaling up quantum computers.
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Affiliation(s)
- Stefano Bosco
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - Daniel Loss
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
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15
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Zhang Y, Jiang M, Wu Z, Yang Q, Men Y, Cheng L, Liang P, Hu R, Jia T, Sun Z, Feng D. Hyperfine-Induced Electron-Spin Dephasing in Negatively Charged Colloidal Quantum Dots: A Survey of Size Dependence. J Phys Chem Lett 2021; 12:9481-9487. [PMID: 34559541 DOI: 10.1021/acs.jpclett.1c02754] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The electron spin relaxation processes are complicated in semiconductor quantum dots. Different spin relaxation mechanisms may result in an increased or decreased spin relaxation rate with the size. The information on size-dependent spin dynamics helps to clarify and better understand the underlying spin relaxation processes. We investigate the size dependence of the electron spin dynamics in negatively photocharged CdSe and CdS colloidal quantum dots by time-resolved ellipticity spectroscopy. It is revealed that the electron spin dephasings of photodoped electron in zero or weak magnetic fields are dominated by the electron-nuclear hyperfine interaction for all measured samples. The hyperfine-induced electron spin dephasing time is ∼1-2 ns at room temperature and decreases with decreasing the size D. In addition to a size-dependent dephasing time that is directly proportional to D3/2, our measurements also show a size-independent time component, likely due to the laser-induced nuclear spin ordering.
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Affiliation(s)
- Yuanyuan Zhang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Meizhen Jiang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Zhen Wu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Qing Yang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Yumeng Men
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Lin Cheng
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Pan Liang
- College of Arts and Sciences, Shanghai Dianji University, Shanghai 201306, China
| | - Rongrong Hu
- College of Sciences, Shanghai Institute of Technology, Shanghai 201418, China
| | - Tianqing Jia
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Zhenrong Sun
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Donghai Feng
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
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16
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Jiang H, Sun C, Yu CM, Wang MS, Guo GC. Broadband Photoresponsive Bismuth Halide Hybrid Semiconductors Built with π-Stacked Photoactive Polycyclic Viologen. Inorg Chem 2021; 60:5538-5544. [PMID: 33830749 DOI: 10.1021/acs.inorgchem.0c03375] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Photoresponse ranges of commercially prevailing photoelectric semiconductors, typically Si and InGaAs, are far from fully covering the whole solar spectrum (∼295-2500 nm), resulting in insufficient solar energy conversion or narrow wave bands for photoelectric detection. Recent studies have shown that infinite π-aggregation of viologen radicals can provide semiconductors with a photoelectric response range covering the solar spectrum. However, controlled assembly of an infinite π-aggregate is still a great challenge in material design. Through directional self-assembly of electron-transfer photoactive polycyclic ligands, two crystalline inorganic-organic hybrid photochromic viologen-based bismuth halide semiconductors, ((Me)3pytpy)[BiCl6]·2H2O [1; (Me)3pytpy = N,N',N″-trimethyl-2,4,6-tris(4-pyridyl)pyridine] and ((Me)3pytpy)[Bi2Cl9]·H2O (2), have been synthesized. They represent the first series of pytpy-based photochromic compounds. After photoinduced coloration, the conductivities of both 1 and 2 increased. The radical products have electron absorption bands in the range of 200-1600 nm, exceeding that of Si. Both the conductivity and the photocurrent intensity of 2 are stronger than those of 1, due to better planarity, tighter π-stacking, and higher degrees of overlap of ((Me)3pytpy)3+ cations. This study not only provides a new design idea for synthesizing radical-based multispectral photoelectric semiconductors but also enriches the family of electron-transfer photochromic compounds.
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Affiliation(s)
- Hui Jiang
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, People's Republic of China.,Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China.,ShanghaiTech University, Shanghai 201210, China.,University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Cai Sun
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, People's Republic of China
| | - Cao-Ming Yu
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, People's Republic of China
| | - Ming-Sheng Wang
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, People's Republic of China
| | - Guo-Cong Guo
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, People's Republic of China
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17
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Wu Z, Zhang Y, Hu R, Jiang M, Liang P, Yang Q, Deng L, Jia T, Sun Z, Feng D. Hole-Acceptor-Manipulated Electron Spin Dynamics in CdSe Colloidal Quantum Dots. J Phys Chem Lett 2021; 12:2126-2132. [PMID: 33625852 DOI: 10.1021/acs.jpclett.0c03669] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Electron spin dynamics in CdSe quantum dots with hole acceptors are investigated by time-resolved ellipticity spectroscopy. Two types of hole acceptors, Li[Et3BH] and 1-octanethiol, result in distinctly different electron spin dynamics. The differences include electron g factors, spin dephasing/relaxation times, and mechanisms. In CdSe quantum dots with Li[Et3BH], the electron spin dephasing and relaxation are dominated by electron-nuclear hyperfine interactions in zero and weak magnetic fields. In contrast, hyperfine interactions, electron carrier lifetimes, and exchange interactions between electrons and holes or surface dangling bond spins control the electron spin dynamics in CdSe quantum dots with 1-octanethiol. Inhomogeneous dephasing limits the spin coherence time in larger transverse magnetic fields for both hole acceptor cases, but with distinct different g-factor inhomogeneity. These findings manifest that surface conditions play an important role in the spin dynamics and that thereby the surface and its surroundings can be exploited to control the spin in colloidal nanostructures.
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Affiliation(s)
- Zhen Wu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Yuanyuan Zhang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Rongrong Hu
- College of Sciences, Shanghai Institute of Technology, Shanghai 201418, China
| | - Meizhen Jiang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Pan Liang
- College of Arts and Sciences, Shanghai Dianji University, Shanghai 201306, China
| | - Qing Yang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Li Deng
- School of Physics & Electronic Science, East China Normal University, Shanghai 200241, China
| | - Tianqing Jia
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Zhenrong Sun
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Donghai Feng
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
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18
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Iversen OA, Pohl T. Strongly Correlated States of Light and Repulsive Photons in Chiral Chains of Three-Level Quantum Emitters. PHYSICAL REVIEW LETTERS 2021; 126:083605. [PMID: 33709742 DOI: 10.1103/physrevlett.126.083605] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 01/06/2021] [Indexed: 06/12/2023]
Abstract
We study the correlated transport of photons through a chain of three-level emitters that are coupled chirally to a photonic mode of a waveguide. It is found that this system can transfer a weak classical input into a strongly correlated state of light in a unitary manner. Our analysis reveals two-photon scattering eigenstates, that are akin to Fano resonances or shape resonances in particle collisions and facilitate the emergence of antibunched light with long-range correlations upon crossing a critical length of the chain. By operating close to conditions of electromagnetically induced transparency of the three-level medium, a high degree of antibunching and photon transmission can be maintained in the presence of moderate losses. These features suggest a promising mechanism for single-photon generation and may open the door to exploring correlated quantum many-body states of light with repulsively interacting photons.
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Affiliation(s)
- Ole A Iversen
- Center for Complex Quantum Systems, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
| | - Thomas Pohl
- Center for Complex Quantum Systems, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
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19
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Appel MH, Tiranov A, Javadi A, Löbl MC, Wang Y, Scholz S, Wieck AD, Ludwig A, Warburton RJ, Lodahl P. Coherent Spin-Photon Interface with Waveguide Induced Cycling Transitions. PHYSICAL REVIEW LETTERS 2021; 126:013602. [PMID: 33480775 DOI: 10.1103/physrevlett.126.013602] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Accepted: 11/24/2020] [Indexed: 06/12/2023]
Abstract
Solid-state quantum dots are promising candidates for efficient light-matter interfaces connecting internal spin degrees of freedom to the states of emitted photons. However, selection rules prevent the combination of efficient spin control and optical cyclicity in this platform. By utilizing a photonic crystal waveguide we here experimentally demonstrate optical cyclicity up to ≈15 through photonic state engineering while achieving high fidelity spin initialization and coherent optical spin control. These capabilities pave the way towards scalable multiphoton entanglement generation and on-chip spin-photon gates.
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Affiliation(s)
- Martin Hayhurst Appel
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | - Alexey Tiranov
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | - Alisa Javadi
- Department of Physics, University of Basel, Klingelbergstraße 82, CH-4056 Basel, Switzerland
| | - Matthias C Löbl
- Department of Physics, University of Basel, Klingelbergstraße 82, CH-4056 Basel, Switzerland
| | - Ying Wang
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | - Sven Scholz
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraße 150, D-44801 Bochum, Germany
| | - Andreas D Wieck
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraße 150, D-44801 Bochum, Germany
| | - Arne Ludwig
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraße 150, D-44801 Bochum, Germany
| | - Richard J Warburton
- Department of Physics, University of Basel, Klingelbergstraße 82, CH-4056 Basel, Switzerland
| | - Peter Lodahl
- Center for Hybrid Quantum Networks (Hy-Q), The Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
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20
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Uppu R, Pedersen FT, Wang Y, Olesen CT, Papon C, Zhou X, Midolo L, Scholz S, Wieck AD, Ludwig A, Lodahl P. Scalable integrated single-photon source. SCIENCE ADVANCES 2020; 6:6/50/eabc8268. [PMID: 33298444 PMCID: PMC7725451 DOI: 10.1126/sciadv.abc8268] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 10/16/2020] [Indexed: 05/27/2023]
Abstract
Photonic qubits are key enablers for quantum information processing deployable across a distributed quantum network. An on-demand and truly scalable source of indistinguishable single photons is the essential component enabling high-fidelity photonic quantum operations. A main challenge is to overcome noise and decoherence processes to reach the steep benchmarks on generation efficiency and photon indistinguishability required for scaling up the source. We report on the realization of a deterministic single-photon source featuring near-unity indistinguishability using a quantum dot in an "on-chip" planar nanophotonic waveguide circuit. The device produces long strings of >100 single photons without any observable decrease in the mutual indistinguishability between photons. A total generation rate of 122 million photons per second is achieved, corresponding to an on-chip source efficiency of 84%. These specifications of the single-photon source are benchmarked for boson sampling and found to enable scaling into the regime of quantum advantage.
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Affiliation(s)
- Ravitej Uppu
- Center for Hybrid Quantum Networks (Hy-Q), Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, DK-2100 Copenhagen, Denmark.
| | - Freja T Pedersen
- Center for Hybrid Quantum Networks (Hy-Q), Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, DK-2100 Copenhagen, Denmark
| | - Ying Wang
- Center for Hybrid Quantum Networks (Hy-Q), Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, DK-2100 Copenhagen, Denmark
| | - Cecilie T Olesen
- Center for Hybrid Quantum Networks (Hy-Q), Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, DK-2100 Copenhagen, Denmark
| | - Camille Papon
- Center for Hybrid Quantum Networks (Hy-Q), Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, DK-2100 Copenhagen, Denmark
| | - Xiaoyan Zhou
- Center for Hybrid Quantum Networks (Hy-Q), Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, DK-2100 Copenhagen, Denmark
| | - Leonardo Midolo
- Center for Hybrid Quantum Networks (Hy-Q), Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, DK-2100 Copenhagen, Denmark
| | - Sven Scholz
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraße 150, D-44780 Bochum, Germany
| | - Andreas D Wieck
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraße 150, D-44780 Bochum, Germany
| | - Arne Ludwig
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraße 150, D-44780 Bochum, Germany
| | - Peter Lodahl
- Center for Hybrid Quantum Networks (Hy-Q), Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, DK-2100 Copenhagen, Denmark.
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21
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Xiong R, Zhang X, Krecker M, Kang S, Smith MJ, Tsukruk VV. Large and Emissive Crystals from Carbon Quantum Dots onto Interfacial Organized Templates. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202008748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Rui Xiong
- School of Materials Science and Engineering Georgia Institute of Technology Atlanta GA 30332-0245 USA
| | - Xiaofang Zhang
- School of Materials Science and Engineering Georgia Institute of Technology Atlanta GA 30332-0245 USA
| | - Michelle Krecker
- School of Materials Science and Engineering Georgia Institute of Technology Atlanta GA 30332-0245 USA
| | - Saewon Kang
- School of Materials Science and Engineering Georgia Institute of Technology Atlanta GA 30332-0245 USA
| | - Marcus J. Smith
- School of Materials Science and Engineering Georgia Institute of Technology Atlanta GA 30332-0245 USA
| | - Vladimir V. Tsukruk
- School of Materials Science and Engineering Georgia Institute of Technology Atlanta GA 30332-0245 USA
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22
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Busatto S, Ruiter MD, Jastrzebski JTBH, Albrecht W, Pinchetti V, Brovelli S, Bals S, Moret ME, de Mello Donega C. Luminescent Colloidal InSb Quantum Dots from In Situ Generated Single-Source Precursor. ACS NANO 2020; 14:13146-13160. [PMID: 32915541 PMCID: PMC7596776 DOI: 10.1021/acsnano.0c04744] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Despite recent advances, the synthesis of colloidal InSb quantum dots (QDs) remains underdeveloped, mostly due to the lack of suitable precursors. In this work, we use Lewis acid-base interactions between Sb(III) and In(III) species formed at room temperature in situ from commercially available compounds (viz., InCl3, Sb[NMe2]3 and a primary alkylamine) to obtain InSb adduct complexes. These complexes are successfully used as precursors for the synthesis of colloidal InSb QDs ranging from 2.8 to 18.2 nm in diameter by fast coreduction at sufficiently high temperatures (≥230 °C). Our findings allow us to propose a formation mechanism for the QDs synthesized in our work, which is based on a nonclassical nucleation event, followed by aggregative growth. This yields ensembles with multimodal size distributions, which can be fractionated in subensembles with relatively narrow polydispersity by postsynthetic size fractionation. InSb QDs with diameters below 7.0 nm have the zinc blende crystal structure, while ensembles of larger QDs (≥10 nm) consist of a mixture of wurtzite and zinc blende QDs. The QDs exhibit photoluminescence with small Stokes shifts and short radiative lifetimes, implying that the emission is due to band-edge recombination and that the direct nature of the bandgap of bulk InSb is preserved in InSb QDs. Finally, we constructed a sizing curve correlating the peak position of the lowest energy absorption transition with the QD diameters, which shows that the band gap of colloidal InSb QDs increases with size reduction following a 1/d dependence.
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Affiliation(s)
- Serena Busatto
- Condensed
Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, P.O. Box 80000, 3508 TA Utrecht, The Netherlands
| | - Mariska de Ruiter
- Condensed
Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, P.O. Box 80000, 3508 TA Utrecht, The Netherlands
| | - Johann T. B. H. Jastrzebski
- Organic
Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Wiebke Albrecht
- Electron
Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - Valerio Pinchetti
- Dipartimento
di Scienza dei Materiali, Università
degli Studi di Milano Bicocca, via Roberto Cozzi 55, I-20125 Milano, Italy
| | - Sergio Brovelli
- Dipartimento
di Scienza dei Materiali, Università
degli Studi di Milano Bicocca, via Roberto Cozzi 55, I-20125 Milano, Italy
| | - Sara Bals
- Electron
Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - Marc-Etienne Moret
- Organic
Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Celso de Mello Donega
- Condensed
Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, P.O. Box 80000, 3508 TA Utrecht, The Netherlands
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23
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Zhang P, Kang Q, Pei Y, Wang Z, Hu Y, Chen Z, Xu J. Unveiling Chiral Phase Evolution in Rabi Oscillations from a Photonic Setting. PHYSICAL REVIEW LETTERS 2020; 125:123201. [PMID: 33016713 DOI: 10.1103/physrevlett.125.123201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 08/05/2020] [Indexed: 06/11/2023]
Abstract
Rabi oscillation, originally proposed in nuclear magnetic resonance, is a well-known phenomenon associated with a driven two-level system. Although magnetic fields typically can bring about chirality into unusual phenomena such as chiral edge states in the quantum Hall effect, it is not clear if chirality exists in Rabi oscillations. Here we unveil the intrinsic chirality carried by the phase in a Rabi problem. For opposite detuning of the driving field, the phase evolution of the probability amplitude exhibits a mirror symmetry. Consequently, constructive or destructive interference of two off-resonant Rabi processes under different initial conditions is level dependent and symmetry protected. Experimentally, we demonstrate such features in a photonic setting with adjustable detuning, yet our results may prove pertinent to the study of similar phenomena in other driven two-level systems beyond photonics.
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Affiliation(s)
- Ping Zhang
- The MOE Key Laboratory of Weak-Light Nonlinear Photonics, TEDA Applied Physics Institute and School of Physics, Nankai University, Tianjin 300457, China
| | - Qianqian Kang
- The MOE Key Laboratory of Weak-Light Nonlinear Photonics, TEDA Applied Physics Institute and School of Physics, Nankai University, Tianjin 300457, China
| | - Yumiao Pei
- The MOE Key Laboratory of Weak-Light Nonlinear Photonics, TEDA Applied Physics Institute and School of Physics, Nankai University, Tianjin 300457, China
| | - Zhaoyuan Wang
- The MOE Key Laboratory of Weak-Light Nonlinear Photonics, TEDA Applied Physics Institute and School of Physics, Nankai University, Tianjin 300457, China
| | - Yi Hu
- The MOE Key Laboratory of Weak-Light Nonlinear Photonics, TEDA Applied Physics Institute and School of Physics, Nankai University, Tianjin 300457, China
| | - Zhigang Chen
- The MOE Key Laboratory of Weak-Light Nonlinear Photonics, TEDA Applied Physics Institute and School of Physics, Nankai University, Tianjin 300457, China
- Department of Physics and Astronomy, San Francisco State University, San Francisco, California 94132, USA
| | - Jingjun Xu
- The MOE Key Laboratory of Weak-Light Nonlinear Photonics, TEDA Applied Physics Institute and School of Physics, Nankai University, Tianjin 300457, China
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24
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Xiong R, Zhang X, Krecker M, Kang S, Smith MJ, Tsukruk VV. Large and Emissive Crystals from Carbon Quantum Dots onto Interfacial Organized Templates. Angew Chem Int Ed Engl 2020; 59:20167-20173. [DOI: 10.1002/anie.202008748] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Indexed: 01/21/2023]
Affiliation(s)
- Rui Xiong
- School of Materials Science and Engineering Georgia Institute of Technology Atlanta GA 30332-0245 USA
| | - Xiaofang Zhang
- School of Materials Science and Engineering Georgia Institute of Technology Atlanta GA 30332-0245 USA
| | - Michelle Krecker
- School of Materials Science and Engineering Georgia Institute of Technology Atlanta GA 30332-0245 USA
| | - Saewon Kang
- School of Materials Science and Engineering Georgia Institute of Technology Atlanta GA 30332-0245 USA
| | - Marcus J. Smith
- School of Materials Science and Engineering Georgia Institute of Technology Atlanta GA 30332-0245 USA
| | - Vladimir V. Tsukruk
- School of Materials Science and Engineering Georgia Institute of Technology Atlanta GA 30332-0245 USA
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25
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Peng L, Chan H, Choo P, Odom TW, Sankaranarayanan SKRS, Ma X. Creation of Single-Photon Emitters in WSe 2 Monolayers Using Nanometer-Sized Gold Tips. NANO LETTERS 2020; 20:5866-5872. [PMID: 32644800 DOI: 10.1021/acs.nanolett.0c01789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Due to their tunable bandgaps and strong spin-valley locking, transition metal dichalcogenides constitute a unique platform for hosting single-photon emitters. Here, we present a versatile approach for creating bright single-photon emitters in WSe2 monolayers by the deposition of gold nanostars. Our molecular dynamics simulations reveal that the formation of the quantum emitters is likely caused by the highly localized strain fields created by the sharp tips of the gold nanostars. The surface plasmon modes supported by the gold nanostars can change the local electromagnetic fields in the vicinity of the quantum emitters, leading to their enhanced emission intensities. Moreover, by correlating the emission energies and intensities of the quantum emitters, we are able to associate them with two types of strain fields and derive the existence of a low-lying dark state in their electronic structures. Our findings are highly relevant for the development and understanding of single-photon emitters in transition metal dichalcogenide materials.
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Affiliation(s)
- Lintao Peng
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Henry Chan
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Priscilla Choo
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Teri W Odom
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Subramanian K R S Sankaranarayanan
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinois 60439, United States
- Department of Mechanical and Industrial Engineering, University of Illinois, Chicago, Illinois 60607, United States
| | - Xuedan Ma
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinois 60439, United States
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26
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Kim S, Le TH, Choi Y, Lee H, Heo E, Lee U, Kim S, Chae S, Kim YA, Yoon H. Electrical monitoring of photoisomerization of block copolymers intercalated into graphene sheets. Nat Commun 2020; 11:1324. [PMID: 32165623 PMCID: PMC7067762 DOI: 10.1038/s41467-020-15132-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 02/19/2020] [Indexed: 12/01/2022] Open
Abstract
Insulating polymers have received little attention in electronic applications. Here, we synthesize a photoresponsive, amphiphilic block copolymer (PEO-b-PVBO) and further control the chain growth of the block segment (PVBO) to obtain different degrees of polymerization (DPs). The benzylidene oxazolone moiety in PEO-b-PVBO facilitated chain-conformational changes due to photoisomerization under visible/ultraviolet (UV) light illumination. Intercalation of the photoresponsive but electrically insulating PEO-b-PVBO into graphene sheets enabled electrical monitoring of the conformational change of the block copolymer at the molecular level. The current change at the microampere level was proportional to the DP of PVBO, demonstrating that the PEO-b-PVBO-intercalated graphene nanohybrid (PGNH) can be used in UV sensors. Additionally, discrete signals at the nanoampere level were separated from the first derivative of the time-dependent current using the fast Fourier transform (FFT). Analysis of the harmonic frequencies using the FFT revealed that the PGNH afforded sawtooth-type current flow mediated by Coulomb blockade oscillation. Block copolymers are electrically insulating and therefore characterization with electrical or electrochemical methods is not possible. Here, the authors demonstrate electrical monitoring of the photoisomerization transition in a benzylidene oxazolone block co-polymer intercalated into graphene sheets.
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Affiliation(s)
- Semin Kim
- Department of Polymer Engineering, Graduate School, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 61186, South Korea
| | - Thanh-Hai Le
- Department of Polymer Engineering, Graduate School, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 61186, South Korea
| | - Yunseok Choi
- Department of Polymer Engineering, Graduate School, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 61186, South Korea
| | - Haney Lee
- Alan G. MacDiarmid Energy Research Institute & School of Polymer Science and Engineering, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 61186, South Korea
| | - Eunseo Heo
- Department of Polymer Engineering, Graduate School, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 61186, South Korea
| | - Unhan Lee
- Department of Polymer Engineering, Graduate School, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 61186, South Korea
| | - Saerona Kim
- Department of Polymer Engineering, Graduate School, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 61186, South Korea
| | - Subin Chae
- Department of Polymer Engineering, Graduate School, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 61186, South Korea
| | - Yoong Ahm Kim
- Department of Polymer Engineering, Graduate School, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 61186, South Korea.,Alan G. MacDiarmid Energy Research Institute & School of Polymer Science and Engineering, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 61186, South Korea
| | - Hyeonseok Yoon
- Department of Polymer Engineering, Graduate School, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 61186, South Korea. .,Alan G. MacDiarmid Energy Research Institute & School of Polymer Science and Engineering, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 61186, South Korea.
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27
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Zhao TM, Chen Y, Yu Y, Li Q, Davanco M, Liu J. Advanced technologies for quantum photonic devices based on epitaxial quantum dots. ADVANCED QUANTUM TECHNOLOGIES 2020; 3:10.1002/qute.201900034. [PMID: 36452403 PMCID: PMC9706462 DOI: 10.1002/qute.201900034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Indexed: 05/12/2023]
Abstract
Quantum photonic devices are candidates for realizing practical quantum computers and networks. The development of integrated quantum photonic devices can greatly benefit from the ability to incorporate different types of materials with complementary, superior optical or electrical properties on a single chip. Semiconductor quantum dots (QDs) serve as a core element in the emerging modern photonic quantum technologies by allowing on-demand generation of single-photons and entangled photon pairs. During each excitation cycle, there is one and only one emitted photon or photon pair. QD photonic devices are on the verge of unfolding for advanced quantum technology applications. In this review, we focus on the latest significant progress of QD photonic devices. We first discuss advanced technologies in QD growth, with special attention to droplet epitaxy and site-controlled QDs. Then we overview the wavelength engineering of QDs via strain tuning and quantum frequency conversion techniques. We extend our discussion to advanced optical excitation techniques recently developed for achieving the desired emission properties of QDs. Finally, the advances in heterogeneous integration of active quantum light-emitting devices and passive integrated photonic circuits are reviewed, in the context of realizing scalable quantum information processing chips.
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Affiliation(s)
- Tian Ming Zhao
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Yan Chen
- Institute for Integrative Nanosciences, Leibniz IFW Dresden, Helmholtzstrasse 20, 01069 Dresden, Germany
| | - Ying Yu
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Qing Li
- Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Marcelo Davanco
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Jin Liu
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China
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28
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Li T, Wang Z, Xia K. Multipartite quantum entanglement creation for distant stationary systems. OPTICS EXPRESS 2020; 28:1316-1329. [PMID: 32121845 DOI: 10.1364/oe.383152] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 12/26/2019] [Indexed: 06/10/2023]
Abstract
We present efficient protocols for creating multipartite Greenberger-Horne-Zeilinger (GHZ) and W states of distant stationary qubits. The system nonuniformity and/or the non-ideal single-photon scattering usually limit the performance of entanglement creation, and result in the decrease of the fidelity and the efficiency in practical quantum information processing. By using linear optical elements, errors caused by the system nonuniformity and non-ideal photon scattering can be converted into heralded loss in our protocols. Thus, the fidelity of generated multipartite entangled states keeps unchanged and only the efficiency decreases. The GHZ state of distant stationary qubits is created in a parallel way that its generation efficiency considerably increases. In the protocol for creating the W state of N distant stationary qubits, an input single photon is prepared in a superposition state and sent into N paths parallelly. We use the two-spatial-mode interferences to eliminate the "which path" single-photon scattering "knowledge". As a result, the efficiency of creating the N-qubit W state is independent of the number of stationary qubits rather than exponentially decreases.
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29
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Luo Z, Sun S, Karasahin A, Bracker AS, Carter SG, Yakes MK, Gammon D, Waks E. A Spin-Photon Interface Using Charge-Tunable Quantum Dots Strongly Coupled to a Cavity. NANO LETTERS 2019; 19:7072-7077. [PMID: 31483668 DOI: 10.1021/acs.nanolett.9b02443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Charged quantum dots containing an electron or hole spin are bright solid-state qubits suitable for quantum networks and distributed quantum computing. Incorporating such quantum dot spin into a photonic crystal cavity creates a strong spin-photon interface in which the spin can control a photon by modulating the cavity reflection coefficient. However, previous demonstrations of such spin-photon interfaces have relied on quantum dots that are charged randomly by nearby impurities, leading to instability in the charge state, which causes poor contrast in the cavity reflectivity. Here we demonstrate a strong spin-photon interface using a quantum dot that is charged deterministically with a diode structure. By incorporating this actively charged quantum dot in a photonic crystal cavity, we achieve strong coupling between the cavity mode and the negatively charged state of the dot. Furthermore, by initializing the spin through optical pumping, we show strong spin-dependent modulation of the cavity reflectivity, corresponding to a cooperativity of 12. This spin-dependent reflectivity is important for mediating entanglement between spins using photons, as well as generating strong photon-photon interactions for applications in quantum networking and distributed quantum computing.
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Affiliation(s)
- Zhouchen Luo
- Department of Electrical and Computer Engineering, Institute for Research in Electronics and Applied Physics, and Joint Quantum Institute , University of Maryland , College Park , Maryland 20742 , United States
| | - Shuo Sun
- Department of Electrical and Computer Engineering, Institute for Research in Electronics and Applied Physics, and Joint Quantum Institute , University of Maryland , College Park , Maryland 20742 , United States
| | - Aziz Karasahin
- Department of Electrical and Computer Engineering, Institute for Research in Electronics and Applied Physics, and Joint Quantum Institute , University of Maryland , College Park , Maryland 20742 , United States
| | - Allan S Bracker
- Naval Research Laboratory , Washington , DC 20375 , United States
| | - Samuel G Carter
- Naval Research Laboratory , Washington , DC 20375 , United States
| | - Michael K Yakes
- Naval Research Laboratory , Washington , DC 20375 , United States
| | - Daniel Gammon
- Naval Research Laboratory , Washington , DC 20375 , United States
| | - Edo Waks
- Department of Electrical and Computer Engineering, Institute for Research in Electronics and Applied Physics, and Joint Quantum Institute , University of Maryland , College Park , Maryland 20742 , United States
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30
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Widmann M, Niethammer M, Fedyanin DY, Khramtsov IA, Rendler T, Booker ID, Ul Hassan J, Morioka N, Chen YC, Ivanov IG, Son NT, Ohshima T, Bockstedte M, Gali A, Bonato C, Lee SY, Wrachtrup J. Electrical Charge State Manipulation of Single Silicon Vacancies in a Silicon Carbide Quantum Optoelectronic Device. NANO LETTERS 2019; 19:7173-7180. [PMID: 31532999 DOI: 10.1021/acs.nanolett.9b02774] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Color centers with long-lived spins are established platforms for quantum sensing and quantum information applications. Color centers exist in different charge states, each of them with distinct optical and spin properties. Application to quantum technology requires the capability to access and stabilize charge states for each specific task. Here, we investigate charge state manipulation of individual silicon vacancies in silicon carbide, a system which has recently shown a unique combination of long spin coherence time and ultrastable spin-selective optical transitions. In particular, we demonstrate charge state switching through the bias applied to the color center in an integrated silicon carbide optoelectronic device. We show that the electronic environment defined by the doping profile and the distribution of other defects in the device plays a key role for charge state control. Our experimental results and numerical modeling evidence that control of these complex interactions can, under certain conditions, enhance the photon emission rate. These findings open the way for deterministic control over the charge state of spin-active color centers for quantum technology and provide novel techniques for monitoring doping profiles and voltage sensing in microscopic devices.
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Affiliation(s)
- Matthias Widmann
- 3. Physikalisches Institut and Research Center SCOPE and Integrated Quantum Science and Technology (IQST) , University of Stuttgart , Pfaffenwaldring 57 , 70569 Stuttgart , Germany
| | - Matthias Niethammer
- 3. Physikalisches Institut and Research Center SCOPE and Integrated Quantum Science and Technology (IQST) , University of Stuttgart , Pfaffenwaldring 57 , 70569 Stuttgart , Germany
| | - Dmitry Yu Fedyanin
- Laboratory of Nanooptics and Plasmonics , Moscow Institute of Physics and Technology , 9 Institutsky Lane , 141700 Dolgoprudny , Russian Federation
| | - Igor A Khramtsov
- Laboratory of Nanooptics and Plasmonics , Moscow Institute of Physics and Technology , 9 Institutsky Lane , 141700 Dolgoprudny , Russian Federation
| | - Torsten Rendler
- 3. Physikalisches Institut and Research Center SCOPE and Integrated Quantum Science and Technology (IQST) , University of Stuttgart , Pfaffenwaldring 57 , 70569 Stuttgart , Germany
| | - Ian D Booker
- Department of Physics, Chemistry and Biology , Linköping University , SE-58183 Linköping , Sweden
| | - Jawad Ul Hassan
- Department of Physics, Chemistry and Biology , Linköping University , SE-58183 Linköping , Sweden
| | - Naoya Morioka
- 3. Physikalisches Institut and Research Center SCOPE and Integrated Quantum Science and Technology (IQST) , University of Stuttgart , Pfaffenwaldring 57 , 70569 Stuttgart , Germany
| | - Yu-Chen Chen
- 3. Physikalisches Institut and Research Center SCOPE and Integrated Quantum Science and Technology (IQST) , University of Stuttgart , Pfaffenwaldring 57 , 70569 Stuttgart , Germany
| | - Ivan G Ivanov
- Department of Physics, Chemistry and Biology , Linköping University , SE-58183 Linköping , Sweden
| | - Nguyen Tien Son
- Department of Physics, Chemistry and Biology , Linköping University , SE-58183 Linköping , Sweden
| | - Takeshi Ohshima
- National Institutes for Quantum and Radiological Science and Technology , Takasaki , Gunma 370-1292 , Japan
| | - Michel Bockstedte
- Department Chemistry and Physics of Materials , University of Salzburg , Jakob-Haringer-Strasse 2a , 5020 Salzburg , Austria
- Solid State Theory , University of Erlangen-Nuremberg , Staudstrasse 7B2 , 91058 Erlangen , Germany
| | - Adam Gali
- Wigner Research Centre for Physics , Hungarian Academy of Sciences , P.O. Box 49, H-1525 Budapest , Hungary
- Department of Atomic Physics , Budapest University of Technology and Economics , Budafoki út 8. , H-1111 Budapest , Hungary
| | - Cristian Bonato
- Institute of Photonics and Quantum Sciences, SUPA , Heriot-Watt University , Edinburgh EH14 4AS , United Kingdom
| | - Sang-Yun Lee
- 3. Physikalisches Institut and Research Center SCOPE and Integrated Quantum Science and Technology (IQST) , University of Stuttgart , Pfaffenwaldring 57 , 70569 Stuttgart , Germany
- Center for Quantum Information , Korea Institute of Science and Technology , Seoul , 02792 , Republic of Korea
| | - Jörg Wrachtrup
- 3. Physikalisches Institut and Research Center SCOPE and Integrated Quantum Science and Technology (IQST) , University of Stuttgart , Pfaffenwaldring 57 , 70569 Stuttgart , Germany
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31
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Heo J, Hong C, Choi SG, Hong JP. Scheme for generation of three-photon entangled W state assisted by cross-Kerr nonlinearity and quantum dot. Sci Rep 2019; 9:10151. [PMID: 31300664 PMCID: PMC6626062 DOI: 10.1038/s41598-019-46231-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 06/24/2019] [Indexed: 12/04/2022] Open
Abstract
We represent an optical scheme using cross-Kerr nonlinearities (XKNLs) and quantum dot (QD) within a single-sided optical cavity (QD-cavity system) to generate three-photon entangled W state containing entanglement against loss of one photon of them. To generate W state (three-photon) with robust entanglement against loss of one photon, we utilize effects of optical nonlinearities in XKNLs (as quantum controlled operations) and QD-cavity system (as a parity operation) with linearly optical devices. In our scheme, the nonlinear (XKNL) gate consists of weak XKNLs, quantum bus beams, and photon-number-resolving measurement to realize controlled-unitary gate between two photons while another nonlinear (QD) gate employs interactions of photons and an electron of QD confined within a single-sided optical cavity for implementation of parity gate. Subsequently, for the efficiency and experimental feasibility of our scheme generating W state, we analyze the immunity of the controlled-unitary gate using XKNLs against decoherence effect and reliable performance of parity gate using QD-cavity system.
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Affiliation(s)
- Jino Heo
- College of Electrical and Computer Engineering, Chungbuk National University, Chungdae-ro 1, Seowon-Gu, Cheongju, Republic of Korea
| | - Changho Hong
- Base Technology Division, National Security Research Institute, P.O. Box 1, Yuseong, Daejeon, 34188, Republic of Korea
| | - Seong-Gon Choi
- College of Electrical and Computer Engineering, Chungbuk National University, Chungdae-ro 1, Seowon-Gu, Cheongju, Republic of Korea
| | - Jong-Phil Hong
- College of Electrical and Computer Engineering, Chungbuk National University, Chungdae-ro 1, Seowon-Gu, Cheongju, Republic of Korea.
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32
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Abstract
A non-reciprocal quantum ring, where one arm of the ring contains the Rashba spin-orbit interaction but not in the other arm, is found to posses very unique electronic properties. In this ring the Aharonov-Bohm oscillations are totally absent. That is because in a magnetic field the electron stays in the non-Rashba arm, while it resides in the Rashba arm for zero (or negative) magnetic field. The average kinetic energy in the two arms of the ring are found to be very different. It also reveals different “spin temperature” in the two arms of the non-reciprocal ring. The electrons are sorted according to their spins in different regions of the ring by switching on and off (or reverse) the magnetic field, thereby creating order without doing work on the system. This resembles the action of a demon in the spirit of Maxwell’s original proposal, exploiting a non-classical internal degree of freedom. Our demon clearly demonstrates some of the required features on the nanoscale.
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33
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Brotons-Gisbert M, Branny A, Kumar S, Picard R, Proux R, Gray M, Burch KS, Watanabe K, Taniguchi T, Gerardot BD. Coulomb blockade in an atomically thin quantum dot coupled to a tunable Fermi reservoir. NATURE NANOTECHNOLOGY 2019; 14:442-446. [PMID: 30858522 DOI: 10.1038/s41565-019-0402-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 02/08/2019] [Indexed: 06/09/2023]
Abstract
Gate-tunable quantum-mechanical tunnelling of particles between a quantum confined state and a nearby Fermi reservoir of delocalized states has underpinned many advances in spintronics and solid-state quantum optics. The prototypical example is a semiconductor quantum dot separated from a gated contact by a tunnel barrier. This enables Coulomb blockade, the phenomenon whereby electrons or holes can be loaded one-by-one into a quantum dot1,2. Depending on the tunnel-coupling strength3,4, this capability facilitates single spin quantum bits1,2,5 or coherent many-body interactions between the confined spin and the Fermi reservoir6,7. Van der Waals (vdW) heterostructures, in which a wide range of unique atomic layers can easily be combined, offer novel prospects to engineer coherent quantum confined spins8,9, tunnel barriers down to the atomic limit10 or a Fermi reservoir beyond the conventional flat density of states11. However, gate-control of vdW nanostructures12-16 at the single particle level is needed to unlock their potential. Here we report Coulomb blockade in a vdW heterostructure consisting of a transition metal dichalcogenide quantum dot coupled to a graphene contact through an atomically thin hexagonal boron nitride (hBN) tunnel barrier. Thanks to a tunable Fermi reservoir, we can deterministically load either a single electron or a single hole into the quantum dot. We observe hybrid excitons, composed of localized quantum dot states and delocalized continuum states, arising from ultra-strong spin-conserving tunnel coupling through the atomically thin tunnel barrier. Probing the charged excitons in applied magnetic fields, we observe large gyromagnetic ratios (∼8). Our results establish a foundation for engineering next-generation devices to investigate either novel regimes of Kondo physics or isolated quantum bits in a vdW heterostructure platform.
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Affiliation(s)
- Mauro Brotons-Gisbert
- Institute of Photonics and Quantum Sciences, SUPA, Heriot-Watt University, Edinburgh, UK.
| | - Artur Branny
- Institute of Photonics and Quantum Sciences, SUPA, Heriot-Watt University, Edinburgh, UK
- Department of Applied Physics, Royal Institute of Technology, Stockholm, Sweden
| | - Santosh Kumar
- Institute of Photonics and Quantum Sciences, SUPA, Heriot-Watt University, Edinburgh, UK
- Indian Institute of Technology, Goa GEC Campus, Ponda, Goa, India
| | - Raphaël Picard
- Institute of Photonics and Quantum Sciences, SUPA, Heriot-Watt University, Edinburgh, UK
| | - Raphaël Proux
- Institute of Photonics and Quantum Sciences, SUPA, Heriot-Watt University, Edinburgh, UK
| | - Mason Gray
- Boston College Department of Physics, Chestnut Hill, MA, USA
| | - Kenneth S Burch
- Boston College Department of Physics, Chestnut Hill, MA, USA
| | - Kenji Watanabe
- National Institute for Materials Science, Tsukuba, Japan
| | | | - Brian D Gerardot
- Institute of Photonics and Quantum Sciences, SUPA, Heriot-Watt University, Edinburgh, UK.
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34
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Abstract
For spin-based quantum computation in semiconductors, dephasing of electron spins by a fluctuating background of nuclear spins is a main obstacle. Here we show that this nuclear background can be precisely controlled in generic quantum dots by periodically exciting electron spins. We demonstrate this universal phenomenon in many-electron GaAs/AlGaAs quantum dot ensembles using optical pump-probe spectroscopy. A feedback mechanism between the electron spin polarization and the nuclear system focuses the electron spin precession frequency into discrete spin modes. Employing such control of nuclear spin polarization, the electron spin lifetime within individual dots can surpass the limit of nuclear background fluctuations, thus substantially enhancing the spin coherence time. This opens the door to achieve long electron spin coherence times also in lithographically defined many-electron systems that can be controlled in shape, size and position.
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35
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Qian C, Xie X, Yang J, Peng K, Wu S, Song F, Sun S, Dang J, Yu Y, Steer MJ, Thayne IG, Jin K, Gu C, Xu X. Enhanced Strong Interaction between Nanocavities and p-shell Excitons Beyond the Dipole Approximation. PHYSICAL REVIEW LETTERS 2019; 122:087401. [PMID: 30932617 DOI: 10.1103/physrevlett.122.087401] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Indexed: 06/09/2023]
Abstract
Large coupling strengths in exciton-photon interactions are important for the quantum photonic network, while strong cavity-quantum dot interactions have been focused on s-shell excitons with small coupling strengths. Here we demonstrate strong interactions between cavities and p-shell excitons with a great enhancement by the in situ wave-function control. The p-shell excitons are demonstrated with much larger wave-function extents and nonlocal interactions beyond the dipole approximation. Then the interaction is tuned from the nonlocal to the local regime by the wave function shrinking, during which the enhancement is obtained. A large coupling strength of 210 μeV has been achieved, indicating the great potential of p-shell excitons for coherent information exchange. Furthermore, we propose a distributed delay model to quantitatively explain the coupling strength variation, revealing the intertwining of excitons and photons beyond the dipole approximation.
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Affiliation(s)
- Chenjiang Qian
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xin Xie
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jingnan Yang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kai Peng
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shiyao Wu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Feilong Song
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Sibai Sun
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jianchen Dang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yang Yu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Matthew J Steer
- School of Engineering, University of Glasgow, Glasgow G12 8LT, United Kingdom
| | - Iain G Thayne
- School of Engineering, University of Glasgow, Glasgow G12 8LT, United Kingdom
| | - Kuijuan Jin
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Changzhi Gu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiulai Xu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
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36
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Hughes S, Agarwal GS. Controlling dipole transparency with magnetic fields. OPTICS LETTERS 2018; 43:5953-5956. [PMID: 30547978 DOI: 10.1364/ol.43.005953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 11/07/2018] [Indexed: 06/09/2023]
Abstract
We describe how magnetic fields can be exploited to control dipole-induced transparency in quantum dot cavity systems. Coupling a linearly-polarized microcavity mode to two spin charged exciton states of a single quantum dot, we demonstrate how cavity-mediated interference and magnetic-field resonance shifts can be utilized to control the transmission of light and on-chip photons, in both magnitude and phase. In particular, we show a triple resonance feature, which also survives with weakly coupled cavities, as long as one operates in the good cooperativity regime. The central peak, which is mediated by the applied magnetic field, is shown to exhibit spectral squeezing. We also demonstrate how the magnetic field allows five regions in which the phase changes by 2π over a small frequency window, where a possible phase gate could be implemented.
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37
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Vukušić L, Kukučka J, Watzinger H, Milem JM, Schäffler F, Katsaros G. Single-Shot Readout of Hole Spins in Ge. NANO LETTERS 2018; 18:7141-7145. [PMID: 30359041 PMCID: PMC6243395 DOI: 10.1021/acs.nanolett.8b03217] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 10/02/2018] [Indexed: 06/08/2023]
Abstract
The strong atomistic spin-orbit coupling of holes makes single-shot spin readout measurements difficult because it reduces the spin lifetimes. By integrating the charge sensor into a high bandwidth radio frequency reflectometry setup, we were able to demonstrate single-shot readout of a germanium quantum dot hole spin and measure the spin lifetime. Hole spin relaxation times of about 90 μs at 500 mT are reported, with a total readout visibility of about 70%. By analyzing separately the spin-to-charge conversion and charge readout fidelities, we have obtained insight into the processes limiting the visibilities of hole spins. The analyses suggest that high hole visibilities are feasible at realistic experimental conditions, underlying the potential of hole spins for the realization of viable qubit devices.
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Affiliation(s)
- Lada Vukušić
- Institute
of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria
| | - Josip Kukučka
- Institute
of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria
| | - Hannes Watzinger
- Institute
of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria
| | - Joshua Michael Milem
- Institute
of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria
| | - Friedrich Schäffler
- Johannes
Kepler University, Institute of Semiconductor and Solid State Physics, Altenbergerstrasse 69, 4040 Linz, Austria
| | - Georgios Katsaros
- Institute
of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria
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38
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Affiliation(s)
- Peter Lodahl
- Hy-Q Center for Hybrid Quantum Networks, Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, DK-2100 Copenhagen, Denmark
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39
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Chen S, Huang Y, Visser D, Anand S, Buyanova IA, Chen WM. Room-temperature polarized spin-photon interface based on a semiconductor nanodisk-in-nanopillar structure driven by few defects. Nat Commun 2018; 9:3575. [PMID: 30177701 PMCID: PMC6120900 DOI: 10.1038/s41467-018-06035-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Accepted: 08/13/2018] [Indexed: 11/24/2022] Open
Abstract
Owing to their superior optical properties, semiconductor nanopillars/nanowires in one-dimensional (1D) geometry are building blocks for nano-photonics. They also hold potential for efficient polarized spin-light conversion in future spin nano-photonics. Unfortunately, spin generation in 1D systems so far remains inefficient at room temperature. Here we propose an approach that can significantly enhance the radiative efficiency of the electrons with the desired spin while suppressing that with the unwanted spin, which simultaneously ensures strong spin and light polarization. We demonstrate high optical polarization of 20%, inferring high electron spin polarization up to 60% at room temperature in a 1D system based on a GaNAs nanodisk-in-GaAs nanopillar structure, facilitated by spin-dependent recombination via merely 2–3 defects in each nanodisk. Our approach points to a promising direction for realization of an interface for efficient spin-photon quantum information transfer at room temperature—a key element for future spin-photonic applications. Room-temperature spin-generation in 1D systems like semiconductor nanopillars is typically inefficient. Here, the authors demonstrate an approach to achieve efficient spin polarization, even in the absence of a magnetic field, by selectively enhancing the radiative efficiency of one spin direction.
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Affiliation(s)
- Shula Chen
- Department of Physics, Chemistry and Biology, Linköping University, SE58183, Linköping, Sweden.
| | - Yuqing Huang
- Department of Physics, Chemistry and Biology, Linköping University, SE58183, Linköping, Sweden
| | - Dennis Visser
- Department of Applied Physics, KTH Royal Institute of Technology, SE16440, Kista, Stockholm, Sweden
| | - Srinivasan Anand
- Department of Applied Physics, KTH Royal Institute of Technology, SE16440, Kista, Stockholm, Sweden
| | - Irina A Buyanova
- Department of Physics, Chemistry and Biology, Linköping University, SE58183, Linköping, Sweden
| | - Weimin M Chen
- Department of Physics, Chemistry and Biology, Linköping University, SE58183, Linköping, Sweden.
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40
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Uniaxial stress flips the natural quantization axis of a quantum dot for integrated quantum photonics. Nat Commun 2018; 9:3058. [PMID: 30076301 PMCID: PMC6076237 DOI: 10.1038/s41467-018-05499-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 07/09/2018] [Indexed: 11/09/2022] Open
Abstract
The optical selection rules in epitaxial quantum dots are strongly influenced by the orientation of their natural quantization axis, which is usually parallel to the growth direction. This configuration is well suited for vertically emitting devices, but not for planar photonic circuits because of the poorly controlled orientation of the transition dipoles in the growth plane. Here we show that the quantization axis of gallium arsenide dots can be flipped into the growth plane via moderate in-plane uniaxial stress. By using piezoelectric strain-actuators featuring strain amplification, we study the evolution of the selection rules and excitonic fine structure in a regime, in which quantum confinement can be regarded as a perturbation compared to strain in determining the symmetry-properties of the system. The experimental and computational results suggest that uniaxial stress may be the right tool to obtain quantum-light sources with ideally oriented transition dipoles and enhanced oscillator strengths for integrated quantum photonics.
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41
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Javadi A, Ding D, Appel MH, Mahmoodian S, Löbl MC, Söllner I, Schott R, Papon C, Pregnolato T, Stobbe S, Midolo L, Schröder T, Wieck AD, Ludwig A, Warburton RJ, Lodahl P. Spin-photon interface and spin-controlled photon switching in a nanobeam waveguide. NATURE NANOTECHNOLOGY 2018; 13:398-403. [PMID: 29556004 DOI: 10.1038/s41565-018-0091-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 02/09/2018] [Indexed: 06/08/2023]
Abstract
The spin of an electron is a promising memory state and qubit. Connecting spin states that are spatially far apart will enable quantum nodes and quantum networks based on the electron spin. Towards this goal, an integrated spin-photon interface would be a major leap forward as it combines the memory capability of a single spin with the efficient transfer of information by photons. Here, we demonstrate such an efficient and optically programmable interface between the spin of an electron in a quantum dot and photons in a nanophotonic waveguide. The spin can be deterministically prepared in the ground state with a fidelity of up to 96%. Subsequently, the system is used to implement a single-spin photonic switch, in which the spin state of the electron directs the flow of photons through the waveguide. The spin-photon interface may enable on-chip photon-photon gates, single-photon transistors and the efficient generation of a photonic cluster state.
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Affiliation(s)
- Alisa Javadi
- Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark.
| | - Dapeng Ding
- Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | | | | | | | - Immo Söllner
- Department of Physics, University of Basel, Basel, Switzerland
| | - Rüdiger Schott
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Bochum, Germany
| | - Camille Papon
- Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | | | - Søren Stobbe
- Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Leonardo Midolo
- Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Tim Schröder
- Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Andreas Dirk Wieck
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Bochum, Germany
| | - Arne Ludwig
- Department of Physics, University of Basel, Basel, Switzerland
| | | | - Peter Lodahl
- Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark.
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42
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Hong CH, Heo J, Kang MS, Jang J, Yang HJ. Optical scheme for generating hyperentanglement having photonic qubit and time-bin via quantum dot and cross-Kerr nonlinearity. Sci Rep 2018; 8:2566. [PMID: 29416070 PMCID: PMC5803275 DOI: 10.1038/s41598-018-19970-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 01/10/2018] [Indexed: 11/16/2022] Open
Abstract
We design an optical scheme to generate hyperentanglement correlated with degrees of freedom (DOFs) via quantum dots (QDs), weak cross-Kerr nonlinearities (XKNLs), and linearly optical apparatuses (including time-bin encoders). For generating hyperentanglement having its own correlations for two DOFs (polarization and time-bin) on two photons, we employ the effects of optical nonlinearities using a QD (photon-electron), a parity gate (XKNLs), and time-bin encodings (linear optics). In our scheme, the first nonlinear multi-qubit gate utilizes the interactions between photons and an electron of QD confined in a single-sided cavity, and the parity gate (second gate) uses weak XKNLs, quantum bus, and photon-number-resolving measurement to entangle the polarizations of two photons. Finally, for efficiency in generating hyperentanglement and for the experimental implementation of this scheme, we discuss how the QD-cavity system can be performed reliably, and also discuss analysis of the immunity of the parity gate (XKNLs) against the decoherence effect.
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Affiliation(s)
- Chang Ho Hong
- Base Technology Division, National Security Research Institute, P.O. Box 1, Yuseong, Daejeon, 34188, Republic of Korea
| | - Jino Heo
- College of Electrical and Computer Engineering, Chungbuk National University, Chungdae-ro 1, Seowon-Gu, Cheongju, Republic of Korea.
| | - Min Sung Kang
- Center for Quantum Information, Korea Institute of Science and Technology (KIST), Seoul, 136-791, Republic of Korea
| | - Jingak Jang
- Base Technology Division, National Security Research Institute, P.O. Box 1, Yuseong, Daejeon, 34188, Republic of Korea
| | - Hyung Jin Yang
- Department of Physics, Korea University, Sejong, 339-700, Republic of Korea
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43
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Heo J, Hong CH, Kang MS, Yang H, Yang HJ, Hong JP, Choi SG. Implementation of controlled quantum teleportation with an arbitrator for secure quantum channels via quantum dots inside optical cavities. Sci Rep 2017; 7:14905. [PMID: 29097727 PMCID: PMC5668345 DOI: 10.1038/s41598-017-14515-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 09/29/2017] [Indexed: 11/09/2022] Open
Abstract
We propose a controlled quantum teleportation scheme to teleport an unknown state based on the interactions between flying photons and quantum dots (QDs) confined within single- and double-sided cavities. In our scheme, users (Alice and Bob) can teleport the unknown state through a secure entanglement channel under the control and distribution of an arbitrator (Trent). For construction of the entanglement channel, Trent utilizes the interactions between two photons and the QD-cavity system, which consists of a charged QD (negatively charged exciton) inside a single-sided cavity. Subsequently, Alice can teleport the unknown state of the electron spin in a QD inside a double-sided cavity to Bob's electron spin in a QD inside a single-sided cavity assisted by the channel information from Trent. Furthermore, our scheme using QD-cavity systems is feasible with high fidelity, and can be experimentally realized with current technologies.
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Affiliation(s)
- Jino Heo
- College of Electrical and Computer Engineering, Chungbuk National University, Chungdae-ro 1, Seowon-Gu, Cheongju, Republic of Korea
| | - Chang-Ho Hong
- National Security Research Institute, P.O. Box 1, Yuseong, Daejeon, 34188, Republic of Korea
| | - Min-Sung Kang
- Center for Quantum Information, Korea Institute of Science and Technology (KIST), Seoul, 136-791, Republic of Korea
| | - Hyeon Yang
- College of Electrical and Computer Engineering, Chungbuk National University, Chungdae-ro 1, Seowon-Gu, Cheongju, Republic of Korea
| | - Hyung-Jin Yang
- Department of Physics, Korea University, Sejong, 339-700, Republic of Korea
| | - Jong-Phil Hong
- College of Electrical and Computer Engineering, Chungbuk National University, Chungdae-ro 1, Seowon-Gu, Cheongju, Republic of Korea
| | - Seong-Gon Choi
- College of Electrical and Computer Engineering, Chungbuk National University, Chungdae-ro 1, Seowon-Gu, Cheongju, Republic of Korea.
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44
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Davanco M, Liu J, Sapienza L, Zhang CZ, De Miranda Cardoso JV, Verma V, Mirin R, Nam SW, Liu L, Srinivasan K. Heterogeneous integration for on-chip quantum photonic circuits with single quantum dot devices. Nat Commun 2017; 8:889. [PMID: 29026109 PMCID: PMC5715121 DOI: 10.1038/s41467-017-00987-6] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 08/09/2017] [Indexed: 12/23/2022] Open
Abstract
Single-quantum emitters are an important resource for photonic quantum technologies, constituting building blocks for single-photon sources, stationary qubits, and deterministic quantum gates. Robust implementation of such functions is achieved through systems that provide both strong light–matter interactions and a low-loss interface between emitters and optical fields. Existing platforms providing such functionality at the single-node level present steep scalability challenges. Here, we develop a heterogeneous photonic integration platform that provides such capabilities in a scalable on-chip implementation, allowing direct integration of GaAs waveguides and cavities containing self-assembled InAs/GaAs quantum dots—a mature class of solid-state quantum emitter—with low-loss Si3N4 waveguides. We demonstrate a highly efficient optical interface between Si3N4 waveguides and single-quantum dots in GaAs geometries, with performance approaching that of devices optimized for each material individually. This includes quantum dot radiative rate enhancement in microcavities, and a path for reaching the non-perturbative strong-coupling regime. Effective use of single emitters in quantum photonics requires coherent emission, strong light-matter coupling, low losses and scalable fabrication. Here, Davanco et al. stride toward this goal by hybrid on-chip integration of Si3N4 waveguides and GaAs nanophotonic geometries with InAs quantum dots.
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Affiliation(s)
- Marcelo Davanco
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA.
| | - Jin Liu
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA. .,School of Physics, Sun-Yat Sen University, Guangzhou, 510275, China. .,Maryland NanoCenter, University of Maryland, College Park, MD, USA.
| | - Luca Sapienza
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA.,Department of Physics & Astronomy, University of Southampton, Southampton, S017 1BJ, UK
| | - Chen-Zhao Zhang
- South China Academy of Advanced Optoelectronics, Science Building No. 5, South China Normal University, Higher-Education Mega-Center, Guangzhou, 510006, China
| | - José Vinícius De Miranda Cardoso
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA.,Federal University of Campina Grande, Campina Grande, Brazil
| | - Varun Verma
- National Institute of Standards and Technology, Boulder, CO, 80305, USA
| | - Richard Mirin
- National Institute of Standards and Technology, Boulder, CO, 80305, USA
| | - Sae Woo Nam
- National Institute of Standards and Technology, Boulder, CO, 80305, USA
| | - Liu Liu
- South China Academy of Advanced Optoelectronics, Science Building No. 5, South China Normal University, Higher-Education Mega-Center, Guangzhou, 510006, China
| | - Kartik Srinivasan
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA.
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45
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Luo JW, Li SS, Zunger A. Rapid Transition of the Hole Rashba Effect from Strong Field Dependence to Saturation in Semiconductor Nanowires. PHYSICAL REVIEW LETTERS 2017; 119:126401. [PMID: 29341631 DOI: 10.1103/physrevlett.119.126401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Indexed: 06/07/2023]
Abstract
The electric field manipulation of the Rashba spin-orbit coupling effects provides a route to electrically control spins, constituting the foundation of the field of semiconductor spintronics. In general, the strength of the Rashba effects depends linearly on the applied electric field and is significant only for heavy-atom materials with large intrinsic spin-orbit interaction under high electric fields. Here, we illustrate in 1D semiconductor nanowires an anomalous field dependence of the hole (but not electron) Rashba effect (HRE). (i) At low fields, the strength of the HRE exhibits a steep increase with the field so that even low fields can be used for device switching. (ii) At higher fields, the HRE undergoes a rapid transition to saturation with a giant strength even for light-atom materials such as Si (exceeding 100 meV Å). (iii) The nanowire-size dependence of the saturation HRE is rather weak for light-atom Si, so size fluctuations would have a limited effect; this is a key requirement for scalability of Rashba-field-based spintronic devices. These three features offer Si nanowires as a promising platform for the realization of scalable complementary metal-oxide-semiconductor compatible spintronic devices.
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Affiliation(s)
- Jun-Wei Luo
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Shu-Shen Li
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Alex Zunger
- Renewable and Sustainable Energy Institute, University of Colorado, Boulder, Colorado 80309, USA
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46
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Szańkowski P, Ramon G, Krzywda J, Kwiatkowski D, Cywiński Ł. Environmental noise spectroscopy with qubits subjected to dynamical decoupling. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:333001. [PMID: 28569239 DOI: 10.1088/1361-648x/aa7648] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A qubit subjected to pure dephasing due to classical Gaussian noise can be turned into a spectrometer of this noise by utilizing its readout under properly chosen dynamical decoupling (DD) sequences to reconstruct the power spectral density of the noise. We review the theory behind this DD-based noise spectroscopy technique, paying special attention to issues that arise when the environmental noise is non-Gaussian and/or it has truly quantum properties. While we focus on the theoretical basis of the method, we connect the discussed concepts with specific experiments, and provide an overview of environmental noise models relevant for solid-state based qubits, including quantum-dot based spin qubits, superconducting qubits, and NV centers in diamond.
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Affiliation(s)
- P Szańkowski
- Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland
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47
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He Y, He YM, Wei YJ, Jiang X, Chen K, Lu CY, Pan JW, Schneider C, Kamp M, Höfling S. Quantum State Transfer from a Single Photon to a Distant Quantum-Dot Electron Spin. PHYSICAL REVIEW LETTERS 2017; 119:060501. [PMID: 28949594 DOI: 10.1103/physrevlett.119.060501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2016] [Indexed: 06/07/2023]
Abstract
Quantum state transfer from flying photons to stationary matter qubits is an important element in the realization of quantum networks. Self-assembled semiconductor quantum dots provide a promising solid-state platform hosting both single photon and spin, with an inherent light-matter interface. Here, we develop a method to coherently and actively control the single-photon frequency bins in superposition using electro-optic modulators, and measure the spin-photon entanglement with a fidelity of 0.796±0.020. Further, by Greenberger-Horne-Zeilinger-type state projection on the frequency, path, and polarization degrees of freedom of a single photon, we demonstrate quantum state transfer from a single photon to a single electron spin confined in an InGaAs quantum dot, separated by 5 m. The quantum state mapping from the photon's polarization to the electron's spin is demonstrated along three different axes on the Bloch sphere, with an average fidelity of 78.5%.
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Affiliation(s)
- Yu He
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Yu-Ming He
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Yu-Jia Wei
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xiao Jiang
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Kai Chen
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Chao-Yang Lu
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Jian-Wei Pan
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Christian Schneider
- Technische Physik, Physikalisches Instität and Wilhelm Conrad Röntgen-Center for Complex Material Systems, Universitat Würzburg, Am Hubland, D-97074 Wüzburg, Germany
| | - Martin Kamp
- Technische Physik, Physikalisches Instität and Wilhelm Conrad Röntgen-Center for Complex Material Systems, Universitat Würzburg, Am Hubland, D-97074 Wüzburg, Germany
| | - Sven Höfling
- Technische Physik, Physikalisches Instität and Wilhelm Conrad Röntgen-Center for Complex Material Systems, Universitat Würzburg, Am Hubland, D-97074 Wüzburg, Germany
- SUPA, School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, United Kingdom
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Chakraborty C, Goodfellow KM, Dhara S, Yoshimura A, Meunier V, Vamivakas AN. Quantum-Confined Stark Effect of Individual Defects in a van der Waals Heterostructure. NANO LETTERS 2017; 17:2253-2258. [PMID: 28267348 DOI: 10.1021/acs.nanolett.6b04889] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The optical properties of atomically thin semiconductor materials have been widely studied because of the isolation of monolayer transition metal dichalcogenides (TMDCs). They have rich optoelectronic properties owing to their large direct bandgap, the interplay between the spin and the valley degree of freedom of charge carriers, and the recently discovered localized excitonic states giving rise to single photon emission. In this Letter, we study the quantum-confined Stark effect of these localized emitters present near the edges of monolayer tungsten diselenide (WSe2). By carefully designing sequences of metallic (graphene), insulating (hexagonal boron nitride), and semiconducting (WSe2) two-dimensional materials, we fabricate a van der Waals heterostructure field effect device with WSe2 hosting quantum emitters that is responsive to external static electric field applied to the device. A very efficient spectral tunability up to 21 meV is demonstrated. Further, evaluation of the spectral shift in the photoluminescence signal as a function of the applied voltage enables us to extract the polarizability volume (up to 2000 Å3) as well as information on the dipole moment of an individual emitter. The Stark shift can be further modulated on application of an external magnetic field, where we observe a flip in the sign of dipole moment possibly due to rearrangement of the position of electron and hole wave functions within the emitter.
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Affiliation(s)
| | | | | | - Anthony Yoshimura
- Department of Physics, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
| | - Vincent Meunier
- Department of Physics, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
| | - A Nick Vamivakas
- Department of Physics, University of Rochester , Rochester, New York 14627, United States
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Photonic transistor and router using a single quantum-dot-confined spin in a single-sided optical microcavity. Sci Rep 2017; 7:45582. [PMID: 28349960 PMCID: PMC5368657 DOI: 10.1038/srep45582] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 02/28/2017] [Indexed: 11/22/2022] Open
Abstract
The future Internet is very likely the mixture of all-optical Internet with low power consumption and quantum Internet with absolute security guaranteed by the laws of quantum mechanics. Photons would be used for processing, routing and com-munication of data, and photonic transistor using a weak light to control a strong light is the core component as an optical analogue to the electronic transistor that forms the basis of modern electronics. In sharp contrast to previous all-optical tran-sistors which are all based on optical nonlinearities, here I introduce a novel design for a high-gain and high-speed (up to terahertz) photonic transistor and its counterpart in the quantum limit, i.e., single-photon transistor based on a linear optical effect: giant Faraday rotation induced by a single electronic spin in a single-sided optical microcavity. A single-photon or classical optical pulse as the gate sets the spin state via projective measurement and controls the polarization of a strong light to open/block the photonic channel. Due to the duality as quantum gate for quantum information processing and transistor for optical information processing, this versatile spin-cavity quantum transistor provides a solid-state platform ideal for all-optical networks and quantum networks.
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Yang W, Ma WL, Liu RB. Quantum many-body theory for electron spin decoherence in nanoscale nuclear spin baths. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2017; 80:016001. [PMID: 27811398 DOI: 10.1088/0034-4885/80/1/016001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Decoherence of electron spins in nanoscale systems is important to quantum technologies such as quantum information processing and magnetometry. It is also an ideal model problem for studying the crossover between quantum and classical phenomena. At low temperatures or in light-element materials where the spin-orbit coupling is weak, the phonon scattering in nanostructures is less important and the fluctuations of nuclear spins become the dominant decoherence mechanism for electron spins. Since the 1950s, semi-classical noise theories have been developed for understanding electron spin decoherence. In spin-based solid-state quantum technologies, the relevant systems are in the nanometer scale and nuclear spin baths are quantum objects which require a quantum description. Recently, quantum pictures have been established to understand the decoherence and quantum many-body theories have been developed to quantitatively describe this phenomenon. Anomalous quantum effects have been predicted and some have been experimentally confirmed. A systematically truncated cluster-correlation expansion theory has been developed to account for the many-body correlations in nanoscale nuclear spin baths that are built up during electron spin decoherence. The theory has successfully predicted and explained a number of experimental results in a wide range of physical systems. In this review, we will cover this recent progress. The limitations of the present quantum many-body theories and possible directions for future development will also be discussed.
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Affiliation(s)
- Wen Yang
- Beijing Computational Science Research Center, Beijing 100193, People's Republic of China
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