1
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Neumeier L, Ciampini MA, Romero-Isart O, Aspelmeyer M, Kiesel N. Fast quantum interference of a nanoparticle via optical potential control. Proc Natl Acad Sci U S A 2024; 121:e2306953121. [PMID: 38227651 PMCID: PMC10823235 DOI: 10.1073/pnas.2306953121] [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: 05/08/2023] [Accepted: 12/08/2023] [Indexed: 01/18/2024] Open
Abstract
We introduce and theoretically analyze a scheme to prepare and detect non-Gaussian quantum states of an optically levitated particle via the interaction with light pulses that generate cubic and inverted potentials. We show that this approach allows to operate on sufficiently short time- and length scales to beat decoherence in a regime accessible in state-of-the-art experiments. Specifically, we predict the observation of single-particle interference of a nanoparticle with a mass above 108 atomic mass units delocalized by several nanometers, on timescales of milliseconds. The proposed experiment uses only optical and electrostatic control, and can be performed at about 10-10 mbar and at room temperature. We discuss the prospect of this method for coherently splitting the wavepacket of massive dielectric objects without using either projective measurements or an internal level structure.
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Affiliation(s)
- Lukas Neumeier
- Vienna Center for Quantum Science and Technology, Faculty of Physics, University of Vienna, ViennaA-1090, Austria
| | - Mario A. Ciampini
- Vienna Center for Quantum Science and Technology, Faculty of Physics, University of Vienna, ViennaA-1090, Austria
| | - Oriol Romero-Isart
- Institute for Quantum Optics and Quantum Information (IQOQI) Innsbruck, Austrian Academy of Sciences, InnsbruckA-6020, Austria
- Institute for Theoretical Physics, School of Mathematics, Computer Science and Physics, University of Innsbruck, InnsbruckA-6020, Austria
| | - Markus Aspelmeyer
- Vienna Center for Quantum Science and Technology, Faculty of Physics, University of Vienna, ViennaA-1090, Austria
- Institute for Quantum Optics and Quantum Information (IQOQI) Vienna, Austrian Academy of Sciences, ViennaA-1090, Austria
| | - Nikolai Kiesel
- Vienna Center for Quantum Science and Technology, Faculty of Physics, University of Vienna, ViennaA-1090, Austria
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2
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Roda-Llordes M, Riera-Campeny A, Candoli D, Grochowski PT, Romero-Isart O. Macroscopic Quantum Superpositions via Dynamics in a Wide Double-Well Potential. PHYSICAL REVIEW LETTERS 2024; 132:023601. [PMID: 38277591 DOI: 10.1103/physrevlett.132.023601] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 12/04/2023] [Indexed: 01/28/2024]
Abstract
We present an experimental proposal for the rapid preparation of the center of mass of a levitated particle in a macroscopic quantum state, that is a state delocalized over a length scale much larger than its zero-point motion and that has no classical analog. This state is prepared by letting the particle evolve in a static double-well potential after a sudden switchoff of the harmonic trap, following initial center-of-mass cooling to a sufficiently pure quantum state. We provide a thorough analysis of the noise and decoherence that is relevant to current experiments with levitated nano- and microparticles. In this context, we highlight the possibility of using two particles, one evolving in each potential well, to mitigate the impact of collective sources of noise and decoherence. The generality and scalability of our proposal make it suitable for implementation with a wide range of systems, including single atoms, ions, and Bose-Einstein condensates. Our results have the potential to enable the generation of macroscopic quantum states at unprecedented scales of length and mass, thereby paving the way for experimental exploration of the gravitational field generated by a source mass in a delocalized quantum state.
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Affiliation(s)
- M Roda-Llordes
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, 6020 Innsbruck, Austria
- Institute for Theoretical Physics, University of Innsbruck, 6020 Innsbruck, Austria
| | - A Riera-Campeny
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, 6020 Innsbruck, Austria
- Institute for Theoretical Physics, University of Innsbruck, 6020 Innsbruck, Austria
| | - D Candoli
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, 6020 Innsbruck, Austria
- Institute for Theoretical Physics, University of Innsbruck, 6020 Innsbruck, Austria
| | - P T Grochowski
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, 6020 Innsbruck, Austria
- Institute for Theoretical Physics, University of Innsbruck, 6020 Innsbruck, Austria
- Center for Theoretical Physics, Polish Academy of Sciences, Aleja Lotników 32/46, 02-668 Warsaw, Poland
| | - O Romero-Isart
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, 6020 Innsbruck, Austria
- Institute for Theoretical Physics, University of Innsbruck, 6020 Innsbruck, Austria
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3
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Bondza SA, Leopold T, Schwarz R, Lisdat C. Achromatic, planar Fresnel-reflector for a single-beam magneto-optical trap. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2024; 95:013202. [PMID: 38270499 DOI: 10.1063/5.0174674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 12/19/2023] [Indexed: 01/26/2024]
Abstract
We present a novel achromatic, planar, periodic mirror structure for single-beam magneto-optical trapping and demonstrate its use in the first- and second-stage cooling and trapping for different isotopes of strontium. We refer to it as a Fresnel magneto-optical trap (MOT) as the structure is inspired by Fresnel lenses. By design, it avoids many of the problems that arise for multi-color cooling using planar structures based on diffraction gratings, which have been the dominant planar structures to be used for single-beam trapping thus far. In addition to a complex design process and cost-intensive fabrication, diffraction gratings suffer from their inherent chromaticity, which causes different axial displacements of trap volumes for different wavelengths and necessitates trade-offs in their diffraction properties and achievable trap depths. In contrast, the Fresnel-reflector structure presented here is a versatile, easy-to-manufacture device that combines achromatic beam steering with the advantages of a planar architecture. It enables miniaturizing trapping systems for alkaline-earth-like atoms with multiple cooling transitions as well as multi-species trapping in the ideal tetrahedral configuration and within the same volume above the structure. Our design presents a novel approach for the miniaturization of cold-atom systems based on single-beam MOTs and enables the widespread adoption of these systems.
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Affiliation(s)
- S A Bondza
- Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany
- Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), Institut für Satellitengeodäsie und Inertialsensorik, Callinstraße 30b, 30167 Hannover, Germany
| | - T Leopold
- Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany
- Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), Institut für Satellitengeodäsie und Inertialsensorik, Callinstraße 30b, 30167 Hannover, Germany
| | - R Schwarz
- Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), Institut für Satellitengeodäsie und Inertialsensorik, Callinstraße 30b, 30167 Hannover, Germany
| | - C Lisdat
- Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany
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4
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Zhao L, Lee MDK, Aliyu MM, Loh H. Floquet-tailored Rydberg interactions. Nat Commun 2023; 14:7128. [PMID: 37932268 PMCID: PMC10628180 DOI: 10.1038/s41467-023-42899-8] [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: 07/08/2023] [Accepted: 10/25/2023] [Indexed: 11/08/2023] Open
Abstract
The Rydberg blockade is a key ingredient for entangling atoms in arrays. However, it requires atoms to be spaced well within the blockade radius, which limits the range of local quantum gates. Here we break this constraint using Floquet frequency modulation, with which we demonstrate Rydberg-blockade entanglement beyond the traditional blockade radius and show how the enlarged entanglement range improves qubit connectivity in a neutral atom array. Further, we find that the coherence of entangled states can be extended under Floquet frequency modulation. Finally, we realize Rydberg anti-blockade states for two sodium Rydberg atoms within the blockade radius. Such Rydberg anti-blockade states for atoms at close range enables the robust preparation of strongly-interacting, long-lived Rydberg states, yet their steady-state population cannot be achieved with only the conventional static drive. Our work transforms between the paradigmatic regimes of Rydberg blockade versus anti-blockade and paves the way for realizing more connected, coherent, and tunable neutral atom quantum processors with a single approach.
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Affiliation(s)
- Luheng Zhao
- Centre for Quantum Technologies, National University of Singapore, 117543, Singapore, Singapore
| | - Michael Dao Kang Lee
- Centre for Quantum Technologies, National University of Singapore, 117543, Singapore, Singapore
| | - Mohammad Mujahid Aliyu
- Centre for Quantum Technologies, National University of Singapore, 117543, Singapore, Singapore
| | - Huanqian Loh
- Centre for Quantum Technologies, National University of Singapore, 117543, Singapore, Singapore.
- Department of Physics, National University of Singapore, 117542, Singapore, Singapore.
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5
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Naldesi P, Elben A, Minguzzi A, Clément D, Zoller P, Vermersch B. Fermionic Correlation Functions from Randomized Measurements in Programmable Atomic Quantum Devices. PHYSICAL REVIEW LETTERS 2023; 131:060601. [PMID: 37625073 DOI: 10.1103/physrevlett.131.060601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 03/16/2023] [Indexed: 08/27/2023]
Abstract
We provide an efficient randomized measurement protocol to estimate two- and four-point fermionic correlations in ultracold atom experiments. Our approach is based on combining random atomic beam splitter operations, which can be realized with programmable optical landscapes, with high-resolution imaging systems such as quantum gas microscopes. We illustrate our results in the context of the variational quantum eigensolver algorithm for solving quantum chemistry problems.
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Affiliation(s)
- Piero Naldesi
- Institute for Theoretical Physics, University of Innsbruck, Innsbruck A-6020, Austria
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, Innsbruck A-6020, Austria
| | - Andreas Elben
- Institute for Theoretical Physics, University of Innsbruck, Innsbruck A-6020, Austria
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, Innsbruck A-6020, Austria
- Institute for Quantum Information and Matter, Caltech, Pasadena, California 91125, USA
- Walter Burke Institute for Theoretical Physics, Caltech, Pasadena, California 91125, USA
| | - Anna Minguzzi
- Univ. Grenoble Alpes, CNRS, LPMMC, 38000 Grenoble, France
| | - David Clément
- Université Paris-Saclay, Institut d'Optique Graduate School, CNRS, Laboratoire Charles Fabry, 91127, Palaiseau, France
| | - Peter Zoller
- Institute for Theoretical Physics, University of Innsbruck, Innsbruck A-6020, Austria
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, Innsbruck A-6020, Austria
| | - Benoît Vermersch
- Institute for Theoretical Physics, University of Innsbruck, Innsbruck A-6020, Austria
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, Innsbruck A-6020, Austria
- Univ. Grenoble Alpes, CNRS, LPMMC, 38000 Grenoble, France
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6
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Ruttley DK, Guttridge A, Spence S, Bird RC, Le Sueur CR, Hutson JM, Cornish SL. Formation of Ultracold Molecules by Merging Optical Tweezers. PHYSICAL REVIEW LETTERS 2023; 130:223401. [PMID: 37327422 DOI: 10.1103/physrevlett.130.223401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/24/2023] [Accepted: 04/25/2023] [Indexed: 06/18/2023]
Abstract
We demonstrate the formation of a single RbCs molecule during the merging of two optical tweezers, one containing a single Rb atom and the other a single Cs atom. Both atoms are initially predominantly in the motional ground states of their respective tweezers. We confirm molecule formation and establish the state of the molecule formed by measuring its binding energy. We find that the probability of molecule formation can be controlled by tuning the confinement of the traps during the merging process, in good agreement with coupled-channel calculations. We show that the conversion efficiency from atoms to molecules using this technique is comparable to magnetoassociation.
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Affiliation(s)
- Daniel K Ruttley
- Department of Physics and Joint Quantum Centre (JQC) Durham-Newcastle, Durham University, South Road, Durham, DH1 3LE, United Kingdom
| | - Alexander Guttridge
- Department of Physics and Joint Quantum Centre (JQC) Durham-Newcastle, Durham University, South Road, Durham, DH1 3LE, United Kingdom
| | - Stefan Spence
- Department of Physics and Joint Quantum Centre (JQC) Durham-Newcastle, Durham University, South Road, Durham, DH1 3LE, United Kingdom
| | - Robert C Bird
- Department of Chemistry and Joint Quantum Centre (JQC) Durham-Newcastle, Durham University, South Road, Durham, DH1 3LE, United Kingdom
| | - C Ruth Le Sueur
- Department of Chemistry and Joint Quantum Centre (JQC) Durham-Newcastle, Durham University, South Road, Durham, DH1 3LE, United Kingdom
| | - Jeremy M Hutson
- Department of Chemistry and Joint Quantum Centre (JQC) Durham-Newcastle, Durham University, South Road, Durham, DH1 3LE, United Kingdom
| | - Simon L Cornish
- Department of Physics and Joint Quantum Centre (JQC) Durham-Newcastle, Durham University, South Road, Durham, DH1 3LE, United Kingdom
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7
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Schlosser M, Tichelmann S, Schäffner D, de Mello DO, Hambach M, Schütz J, Birkl G. Scalable Multilayer Architecture of Assembled Single-Atom Qubit Arrays in a Three-Dimensional Talbot Tweezer Lattice. PHYSICAL REVIEW LETTERS 2023; 130:180601. [PMID: 37204875 DOI: 10.1103/physrevlett.130.180601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 03/27/2023] [Indexed: 05/21/2023]
Abstract
We report on the realization of a novel platform for the creation of large-scale 3D multilayer configurations of planar arrays of individual neutral-atom qubits: a microlens-generated Talbot tweezer lattice that extends 2D tweezer arrays to the third dimension at no additional costs. We demonstrate the trapping and imaging of rubidium atoms in integer and fractional Talbot planes and the assembly of defect-free atom arrays in different layers. The Talbot self-imaging effect for microlens arrays constitutes a structurally robust and wavelength-universal method for the realization of 3D atom arrays with beneficial scaling properties. With more than 750 qubit sites per 2D layer, these scaling properties imply that 10 000 qubit sites are already accessible in 3D in our current implementation. The trap topology and functionality are configurable in the micrometer regime. We use this to generate interleaved lattices with dynamic position control and parallelized sublattice addressing of spin states for immediate application in quantum science and technology.
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Affiliation(s)
- Malte Schlosser
- Technische Universität Darmstadt, Institut für Angewandte Physik, Schlossgartenstraße 7, 64289 Darmstadt, Germany
| | - Sascha Tichelmann
- Technische Universität Darmstadt, Institut für Angewandte Physik, Schlossgartenstraße 7, 64289 Darmstadt, Germany
| | - Dominik Schäffner
- Technische Universität Darmstadt, Institut für Angewandte Physik, Schlossgartenstraße 7, 64289 Darmstadt, Germany
| | - Daniel Ohl de Mello
- Technische Universität Darmstadt, Institut für Angewandte Physik, Schlossgartenstraße 7, 64289 Darmstadt, Germany
| | - Moritz Hambach
- Technische Universität Darmstadt, Institut für Angewandte Physik, Schlossgartenstraße 7, 64289 Darmstadt, Germany
| | - Jan Schütz
- Technische Universität Darmstadt, Institut für Angewandte Physik, Schlossgartenstraße 7, 64289 Darmstadt, Germany
| | - Gerhard Birkl
- Technische Universität Darmstadt, Institut für Angewandte Physik, Schlossgartenstraße 7, 64289 Darmstadt, Germany
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8
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McGilligan JP, Gallacher K, Griffin PF, Paul DJ, Arnold AS, Riis E. Micro-fabricated components for cold atom sensors. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:091101. [PMID: 36182455 DOI: 10.1063/5.0101628] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 08/02/2022] [Indexed: 06/16/2023]
Abstract
Laser cooled atoms have proven transformative for precision metrology, playing a pivotal role in state-of-the-art clocks and interferometers and having the potential to provide a step-change in our modern technological capabilities. To successfully explore their full potential, laser cooling platforms must be translated from the laboratory environment and into portable, compact quantum sensors for deployment in practical applications. This transition requires the amalgamation of a wide range of components and expertise if an unambiguously chip-scale cold atom sensor is to be realized. We present recent developments in cold-atom sensor miniaturization, focusing on key components that enable laser cooling on the chip-scale. The design, fabrication, and impact of the components on sensor scalability and performance will be discussed with an outlook to the next generation of chip-scale cold atom devices.
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Affiliation(s)
- J P McGilligan
- SUPA and Department of Physics, University of Strathclyde, Glasgow G4 0NG, United Kingdom
| | - K Gallacher
- James Watt School of Engineering, University of Glasgow, Glasgow G12 8LT, United Kingdom
| | - P F Griffin
- SUPA and Department of Physics, University of Strathclyde, Glasgow G4 0NG, United Kingdom
| | - D J Paul
- James Watt School of Engineering, University of Glasgow, Glasgow G12 8LT, United Kingdom
| | - A S Arnold
- SUPA and Department of Physics, University of Strathclyde, Glasgow G4 0NG, United Kingdom
| | - E Riis
- SUPA and Department of Physics, University of Strathclyde, Glasgow G4 0NG, United Kingdom
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9
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Fernández-Fernández D, González-Tudela A. Tunable Directional Emission and Collective Dissipation with Quantum Metasurfaces. PHYSICAL REVIEW LETTERS 2022; 128:113601. [PMID: 35363033 DOI: 10.1103/physrevlett.128.113601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 01/26/2022] [Indexed: 06/14/2023]
Abstract
Subwavelength atomic arrays, recently labeled as quantum metamaterials, have emerged as an exciting platform for obtaining novel quantum optical phenomena. The strong interference effects in these systems generate subradiant excitations that propagate through the atomic array with very long lifetimes. Here, we demonstrate that one can harness these excitations to obtain tunable directional emission patterns and collective dissipative couplings when placing judiciously additional atoms nearby the atomic array. For doing that, we first characterize the optimal square array geometry to obtain directional emission patterns. Then, we characterize the best atomic positions to couple efficiently to the subradiant metasurface excitations and provide several improvement strategies based on entangled atomic clusters or bilayers. Afterward, we also show how the directionality of the emission pattern can be controlled through the relative dipole orientation between the auxiliary atoms and the one of the array. Finally, we benchmark how these directional emission patterns translate into to collective, anisotropic dissipative couplings between the auxiliary atoms by studying the lifetime modification of atomic entangled states.
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Affiliation(s)
- D Fernández-Fernández
- Institute of Fundamental Physics IFF-CSIC, Calle Serrano 113b, 28006 Madrid, Spain
- Instituto de Ciencia de Materiales de Madrid ICMM-CSIC, 28049 Madrid, Spain
| | - A González-Tudela
- Institute of Fundamental Physics IFF-CSIC, Calle Serrano 113b, 28006 Madrid, Spain
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10
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Bianchet LC, Alves N, Zarraoa L, Bruno N, Mitchell MW. Manipulating and measuring single atoms in the Maltese cross geometry. OPEN RESEARCH EUROPE 2022; 1:102. [PMID: 37645131 PMCID: PMC10446080 DOI: 10.12688/openreseurope.13972.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/11/2022] [Indexed: 08/31/2023]
Abstract
Background: Optical microtraps at the focus of high numerical aperture (high-NA) imaging systems enable efficient collection, trapping, detection and manipulation of individual neutral atoms for quantum technology and studies of optical physics associated with super- and sub-radiant states. The recently developed "Maltese cross" geometry (MCG) atom trap uses four in-vacuum lenses to achieve four-directional high-NA optical coupling to single trapped atoms and small atomic arrays. This article presents the first extensive characterisation of atomic behaviour in a MCG atom trap. Methods: We employ a MCG system optimised for high coupling efficiency and characterise the resulting properties of the trap and trapped atoms. Using current best practices, we measure occupancy, loading rate, lifetime, temperature, fluorescence anti-bunching and trap frequencies. We also use the four-directional access to implement a new method to map the spatial distribution of collection efficiency from high-NA optics: we use the two on-trap-axis lenses to produce a 1D optical lattice, the sites of which are stochastically filled and emptied by the trap loading process. The two off-trap-axis lenses are used for imaging and single-mode collection. Correlations of single-mode and imaging fluorescence signals are then used to map the single-mode collection efficiency. Results: We observe trap characteristics comparable to what has been reported for single-atom traps with one- or two-lens optical systems. The collection efficiency distribution in the axial and transverse directions is directly observed to be in agreement with expected collection efficiency distribution from Gaussian beam optics. Conclusions: The multi-directional high-NA access provided by the Maltese cross geometry enables complex manipulations and measurements not possible in geometries with fewer directions of access, and can be achieved while preserving other trap characteristics such as lifetime, temperature, and trap size.
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Affiliation(s)
- Lorena C. Bianchet
- ICFO - Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, 08860, Spain
| | - Natalia Alves
- ICFO - Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, 08860, Spain
| | - Laura Zarraoa
- ICFO - Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, 08860, Spain
| | - Natalia Bruno
- Istituto Nazionale di Ottica (CNR-INO), Largo Enrico Fermi 6, Florence, 50125, Italy
- European Laboratory for Non-linear Spectroscopy (LENS), Via nello Carrara 1, 50019 Sesto Fiorentino, Florence, Italy
| | - Morgan W. Mitchell
- ICFO - Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, 08860, Spain
- ICREA - Institució Catalana de Recerca i Estudis Avançats, Barcelona, 08010, Spain
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11
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Hartke T, Oreg B, Jia N, Zwierlein M. Quantum register of fermion pairs. Nature 2022; 601:537-541. [PMID: 35082420 DOI: 10.1038/s41586-021-04205-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 11/03/2021] [Indexed: 11/09/2022]
Abstract
Quantum control of motion is central for modern atomic clocks1 and interferometers2. It enables protocols to process and distribute quantum information3,4, and allows the probing of entanglement in correlated states of matter5. However, the motional coherence of individual particles can be fragile to maintain, as external degrees of freedom couple strongly to the environment. Systems in nature with robust motional coherence instead often involve pairs of particles, from the electrons in helium, to atom pairs6, molecules7 and Cooper pairs. Here we demonstrate long-lived motional coherence and entanglement of pairs of fermionic atoms in an optical lattice array. The common and relative motion of each pair realize a robust qubit, protected by exchange symmetry. The energy difference between the two motional states is set by the atomic recoil energy, is dependent on only the mass and the lattice wavelength, and is insensitive to the noise of the confining potential. We observe quantum coherence beyond ten seconds. Modulation of the interactions between the atoms provides universal control of the motional qubit. The methods presented here will enable coherently programmable quantum simulators of many-fermion systems8, precision metrology based on atom pairs and molecules9,10 and, by implementing further advances11-13, digital quantum computation using fermion pairs14.
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Affiliation(s)
- Thomas Hartke
- Department of Physics, MIT-Harvard Center for Ultracold Atoms, Research Laboratory of Electronics, MIT, Cambridge, MA, USA.
| | - Botond Oreg
- Department of Physics, MIT-Harvard Center for Ultracold Atoms, Research Laboratory of Electronics, MIT, Cambridge, MA, USA
| | - Ningyuan Jia
- Department of Physics, MIT-Harvard Center for Ultracold Atoms, Research Laboratory of Electronics, MIT, Cambridge, MA, USA
| | - Martin Zwierlein
- Department of Physics, MIT-Harvard Center for Ultracold Atoms, Research Laboratory of Electronics, MIT, Cambridge, MA, USA.
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12
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Qian ZH, Cui JM, Luo XW, Zheng YX, Huang YF, Ai MZ, He R, Li CF, Guo GC. Super-resolved Imaging of a Single Cold Atom on a Nanosecond Timescale. PHYSICAL REVIEW LETTERS 2021; 127:263603. [PMID: 35029497 DOI: 10.1103/physrevlett.127.263603] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 10/03/2021] [Accepted: 11/29/2021] [Indexed: 06/14/2023]
Abstract
In cold atomic systems, fast and high-resolution microscopy of individual atoms is crucial, since it can provide direct information on the dynamics and correlations of the system. Here, we demonstrate nanosecond-scale two-dimensional stroboscopic pictures of a single trapped ion beyond the optical diffraction limit, by combining the main idea of ground-state depletion microscopy with quantum-state transition control in cold atoms. We achieve a spatial resolution up to 175 nm using a NA=0.1 objective in the experiment, which represents a more than tenfold improvement compared with direct fluorescence imaging. To show the potential of this method, we apply it to observe the secular motion of the trapped ion; we demonstrate a temporal resolution up to 50 ns with a displacement detection sensitivity of 10 nm. Our method provides a powerful tool for probing particle positions, momenta, and correlations, as well as their dynamics in cold atomic systems.
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Affiliation(s)
- Zhong-Hua Qian
- CAS Key Laboratory of Quantum Information, 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
| | - Jin-Ming Cui
- CAS Key Laboratory of Quantum Information, 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
| | - Xi-Wang Luo
- CAS Key Laboratory of Quantum Information, 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
| | - Yong-Xiang Zheng
- CAS Key Laboratory of Quantum Information, 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
| | - Yun-Feng Huang
- CAS Key Laboratory of Quantum Information, 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
| | - Ming-Zhong Ai
- CAS Key Laboratory of Quantum Information, 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
| | - Ran He
- CAS Key Laboratory of Quantum Information, 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
| | - Chuan-Feng Li
- CAS Key Laboratory of Quantum Information, 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
| | - Guang-Can Guo
- CAS Key Laboratory of Quantum Information, 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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13
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Kolbow JD, Lindquist NC, Ertsgaard CT, Yoo D, Oh SH. Nano-Optical Tweezers: Methods and Applications for Trapping Single Molecules and Nanoparticles. Chemphyschem 2021; 22:1409-1420. [PMID: 33797179 DOI: 10.1002/cphc.202100004] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 03/31/2021] [Indexed: 11/10/2022]
Abstract
Optical tweezers were developed in 1970 by Arthur Ashkin as a tool for the manipulation of micron-sized particles. Ashkin's original design was then adapted for a variety of purposes, such as trapping and manipulation of biological materials[1] and the laser cooling of atoms.[2,3] More recent development has led to nano-optical tweezers, for trapping particles on the scale of only a few nanometers, and holographic tweezers, which allow for dynamic control of multiple traps in real-time. These alternatives to conventional optical tweezers have made it possible to trap single molecules and to perform a variety of studies on them. Presented here is a review of recent developments in nano-optical tweezers and their current and future applications.
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Affiliation(s)
- Joshua D Kolbow
- Department of Electrical and Computer Engineering, University of Minnesota Kenneth H. Keller Hall, 200, Union St SE, Minneapolis, MN 55455, USA
| | - Nathan C Lindquist
- Department of Physics and Engineering, Bethel University, 3900 Bethel Drive, St. Paul, MN 55112, USA
| | - Christopher T Ertsgaard
- Department of Electrical and Computer Engineering, University of Minnesota Kenneth H. Keller Hall, 200, Union St SE, Minneapolis, MN 55455, USA
| | - Daehan Yoo
- Department of Electrical and Computer Engineering, University of Minnesota Kenneth H. Keller Hall, 200, Union St SE, Minneapolis, MN 55455, USA
| | - Sang-Hyun Oh
- Department of Electrical and Computer Engineering, University of Minnesota Kenneth H. Keller Hall, 200, Union St SE, Minneapolis, MN 55455, USA
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14
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Ding S, Wu Y, Finneran IA, Burau JJ, Ye J. Sub-Doppler Cooling and Compressed Trapping of YO Molecules at μK Temperatures. PHYSICAL REVIEW. X 2020; 10:10.1103/physrevx.10.021049. [PMID: 33643688 PMCID: PMC7909871 DOI: 10.1103/physrevx.10.021049] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Complex molecular structure demands customized solutions to laser cooling by extending its general set of principles and practices. Compared with other laser-cooled molecules, yttrium monoxide (YO) exhibits a large electron-nucleus interaction, resulting in a dominant hyperfine interaction over the electron spin-rotation coupling. The YO ground state is thus comprised of two manifolds of closely spaced states, with one of them possessing a negligible Landé g factor. This unique energy level structure favors dual-frequency dc magneto-optical trapping (MOT) and gray molasses cooling (GMC). We report exceptionally robust cooling of YO at 4 μK over a wide range of laser intensity, detunings (one- and two-photon), and magnetic field. The magnetic insensitivity enables the spatial compression of the molecular cloud by alternating GMC and MOT under the continuous operation of the quadrupole magnetic field. A combination of these techniques produces a laser-cooled molecular sample with the highest phase space density in free space.
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Affiliation(s)
- Shiqian Ding
- JILA, National Institute of Standards and Technology and the University of Colorado, Boulder, Colorado 80309-0440, USA; Department of Physics, University of Colorado, Boulder, Colorado 80309-0390, USA
| | - Yewei Wu
- JILA, National Institute of Standards and Technology and the University of Colorado, Boulder, Colorado 80309-0440, USA; Department of Physics, University of Colorado, Boulder, Colorado 80309-0390, USA
| | - Ian A. Finneran
- JILA, National Institute of Standards and Technology and the University of Colorado, Boulder, Colorado 80309-0440, USA; Department of Physics, University of Colorado, Boulder, Colorado 80309-0390, USA
| | - Justin J. Burau
- JILA, National Institute of Standards and Technology and the University of Colorado, Boulder, Colorado 80309-0440, USA; Department of Physics, University of Colorado, Boulder, Colorado 80309-0390, USA
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15
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Lucchesi L, Chiofalo ML. Many-Body Entanglement in Short-Range Interacting Fermi Gases for Metrology. PHYSICAL REVIEW LETTERS 2019; 123:060406. [PMID: 31491136 DOI: 10.1103/physrevlett.123.060406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 06/20/2019] [Indexed: 06/10/2023]
Abstract
We explore many-body entanglement in spinful Fermi gases with short-range interactions, for metrology purposes. We characterize the emerging quantum phases via density-matrix renormalization group simulations and quantify their entanglement content for metrological usability via quantum Fisher information (QFI). Our study establishes a method, promoting QFI to be an order parameter. Short-range interactions reveal to build up metrologically promising entanglement in the XY-ferromagnetic and cluster ordering, the cluster physics being unexplored so far.
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Affiliation(s)
- Leonardo Lucchesi
- Dipartimento di Fisica "Enrico Fermi" and INFN, Università di Pisa, Largo B. Pontecorvo 3, I-56127 Pisa, Italy
| | - Maria Luisa Chiofalo
- Dipartimento di Fisica "Enrico Fermi" and INFN, Università di Pisa, Largo B. Pontecorvo 3, I-56127 Pisa, Italy
- JILA, University of Colorado, 440 UCB, Boulder, Colorado 80309, USA
- Kavli Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106-4030, USA
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16
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Ohl de Mello D, Schäffner D, Werkmann J, Preuschoff T, Kohfahl L, Schlosser M, Birkl G. Defect-Free Assembly of 2D Clusters of More Than 100 Single-Atom Quantum Systems. PHYSICAL REVIEW LETTERS 2019; 122:203601. [PMID: 31172754 DOI: 10.1103/physrevlett.122.203601] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Indexed: 06/09/2023]
Abstract
We demonstrate the defect-free assembly of versatile target patterns of up 111 neutral atoms, building on a 361-site subset of a micro-optical architecture that readily provides thousands of sites for single-atom quantum systems. By performing multiple assembly cycles in rapid succession, we drastically increase achievable structure sizes and success probabilities. We implement repeated target pattern reconstruction after atom loss and deterministic transport of partial atom clusters necessary for distributing entanglement in large-scale systems. This technique will propel assembled-atom architectures beyond the threshold of quantum advantage and into a regime with abundant applications in quantum sensing and metrology, Rydberg-state mediated quantum simulation, and error-corrected quantum computation.
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Affiliation(s)
- Daniel Ohl de Mello
- Institut für Angewandte Physik, Technische Universität Darmstadt, Schlossgartenstraße 7, 64289 Darmstadt, Germany
| | - Dominik Schäffner
- Institut für Angewandte Physik, Technische Universität Darmstadt, Schlossgartenstraße 7, 64289 Darmstadt, Germany
| | - Jan Werkmann
- Institut für Angewandte Physik, Technische Universität Darmstadt, Schlossgartenstraße 7, 64289 Darmstadt, Germany
| | - Tilman Preuschoff
- Institut für Angewandte Physik, Technische Universität Darmstadt, Schlossgartenstraße 7, 64289 Darmstadt, Germany
| | - Lars Kohfahl
- Institut für Angewandte Physik, Technische Universität Darmstadt, Schlossgartenstraße 7, 64289 Darmstadt, Germany
| | - Malte Schlosser
- Institut für Angewandte Physik, Technische Universität Darmstadt, Schlossgartenstraße 7, 64289 Darmstadt, Germany
| | - Gerhard Birkl
- Institut für Angewandte Physik, Technische Universität Darmstadt, Schlossgartenstraße 7, 64289 Darmstadt, Germany
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17
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Sompet P, Szigeti SS, Schwartz E, Bradley AS, Andersen MF. Thermally robust spin correlations between two 85Rb atoms in an optical microtrap. Nat Commun 2019; 10:1889. [PMID: 31015406 PMCID: PMC6478867 DOI: 10.1038/s41467-019-09420-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 03/11/2019] [Indexed: 11/21/2022] Open
Abstract
The complex collisional properties of atoms fundamentally limit investigations into a range of processes in many-atom ensembles. In contrast, the bottom-up assembly of few- and many-body systems from individual atoms offers a controlled approach to isolating and studying such collisional processes. Here, we use optical tweezers to individually assemble pairs of trapped 85Rb atoms, and study the spin dynamics of the two-body system in a thermal state. The spin-2 atoms show strong pair correlation between magnetic sublevels on timescales exceeding one second, with measured relative number fluctuations 11.9 ± 0.3 dB below quantum shot noise, limited only by detection efficiency. Spin populations display relaxation dynamics consistent with simulations and theoretical predictions for 85Rb spin interactions, and contrary to the coherent spin waves witnessed in finite-temperature many-body experiments and zero-temperature two-body experiments. Our experimental approach offers a versatile platform for studying two-body quantum dynamics and may provide a route to thermally robust entanglement generation. Spin-changing atomic collisions are important for thermally robust entanglement generation with applications in quantum information. Here the authors demonstrate record high spin state correlations and long spin relaxation times in the collision of two Rb atoms at relatively warm temperatures.
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Affiliation(s)
- Pimonpan Sompet
- The Dodd-Walls Centre for Photonic and Quantum Technologies, Department of Physics, University of Otago, Dunedin, New Zealand.,Max-Planck-Institut für Quantenoptik, 85748, Garching, Germany
| | - Stuart S Szigeti
- The Dodd-Walls Centre for Photonic and Quantum Technologies, Department of Physics, University of Otago, Dunedin, New Zealand.,Department of Quantum Science, Research School of Physics and Engineering, The Australian National University, Canberra, ACT, 2601, Australia
| | - Eyal Schwartz
- The Dodd-Walls Centre for Photonic and Quantum Technologies, Department of Physics, University of Otago, Dunedin, New Zealand
| | - Ashton S Bradley
- The Dodd-Walls Centre for Photonic and Quantum Technologies, Department of Physics, University of Otago, Dunedin, New Zealand
| | - Mikkel F Andersen
- The Dodd-Walls Centre for Photonic and Quantum Technologies, Department of Physics, University of Otago, Dunedin, New Zealand.
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18
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Saskin S, Wilson JT, Grinkemeyer B, Thompson JD. Narrow-Line Cooling and Imaging of Ytterbium Atoms in an Optical Tweezer Array. PHYSICAL REVIEW LETTERS 2019; 122:143002. [PMID: 31050452 DOI: 10.1103/physrevlett.122.143002] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Indexed: 06/09/2023]
Abstract
Engineering controllable, strongly interacting many-body quantum systems is at the frontier of quantum simulation and quantum information processing. Arrays of laser-cooled neutral atoms in optical tweezers have emerged as a promising platform because of their flexibility and the potential for strong interactions via Rydberg states. Existing neutral atom array experiments utilize alkali atoms, but alkaline-earth atoms offer many advantages in terms of coherence and control, and also open the door to new applications in precision measurement and time keeping. In this Letter, we present a technique to trap individual alkaline-earth-like ytterbium (Yb) atoms in optical tweezer arrays. The narrow ^{1}S_{0}-^{3}P_{1} intercombination line is used for both cooling and imaging in a magic-wavelength optical tweezer at 532 nm. The low Doppler temperature allows for imaging near the saturation intensity, resulting in a very high atom detection fidelity. We demonstrate the imaging fidelity concretely by observing rare (<1 in 10^{4} images) spontaneous quantum jumps into and out of a metastable state. We also demonstrate stochastic loading of atoms into a two-dimensional, 144-site tweezer array. This platform will enable advances in quantum information processing, quantum simulation, and precision measurement. The demonstrated narrow-line Doppler imaging may also be applied in tweezer arrays or quantum gas microscopes using other atoms with similar transitions, such as erbium and dysprosium.
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Affiliation(s)
- S Saskin
- Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08540, USA
- Department of Physics, Princeton University, Princeton, New Jersey 08540, USA
| | - J T Wilson
- Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08540, USA
| | - B Grinkemeyer
- Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08540, USA
| | - J D Thompson
- Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08540, USA
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19
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20
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Entanglement of bosonic modes through an engineered exchange interaction. Nature 2019; 566:509-512. [DOI: 10.1038/s41586-019-0970-4] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 01/17/2019] [Indexed: 11/08/2022]
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21
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Abstract
Although constructing a quantum computation device with multiple qubits is arguably a difficult task, several seconds of coherence time with tens of thousands of quantum particles has been demonstrated with a trapped atomic ensemble. As a practical application, a security-enhanced quantum state memory using atoms has been demonstrated. It was shown that the quantum superposition preserved in an atomic ensemble was scrambled and faithfully descrambled; however, the scrambled phase ambiguity remained at 50%. To overcome this problem, we propose and demonstrate a scheme that achieves 100% phase ambiguity without introducing an extra Ramsey interferometer. Moreover, this scheme can be used as a direct application to keep the choice between two values secret without falsification.
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22
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Schmidt F, Mayer D, Bouton Q, Adam D, Lausch T, Spethmann N, Widera A. Quantum Spin Dynamics of Individual Neutral Impurities Coupled to a Bose-Einstein Condensate. PHYSICAL REVIEW LETTERS 2018; 121:130403. [PMID: 30312071 DOI: 10.1103/physrevlett.121.130403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Indexed: 06/08/2023]
Abstract
We report on spin dynamics of individual, localized neutral impurities immersed in a Bose-Einstein condensate. Single cesium atoms are transported into a cloud of rubidium atoms and thermalize with the bath, and the ensuing spin exchange between localized impurities with quasispin F_{i}=3 and bath atoms with F_{b}=1 is resolved. Comparing our data to numerical simulations of spin dynamics, we find that, for gas densities in the Bose-Einstein condensate regime, the dynamics is dominated by the condensed fraction of the cloud. We spatially resolve the density overlap of impurities and gas by the spin population of impurities. Finally, we trace the coherence of impurities prepared in a coherent superposition of internal states when coupled to a gas of different densities. For our choice of states, we show that, despite high bath densities and, thus, fast thermalization rates, the impurity coherence is not affected by the bath, realizing a regime of sympathetic cooling while maintaining internal state coherence. Our work paves the way toward the nondestructive probing of quantum many-body systems via localized impurities.
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Affiliation(s)
- Felix Schmidt
- Department of Physics and Research Center OPTIMAS, Technische Universität Kaiserslautern, Germany
| | - Daniel Mayer
- Department of Physics and Research Center OPTIMAS, Technische Universität Kaiserslautern, Germany
| | - Quentin Bouton
- Department of Physics and Research Center OPTIMAS, Technische Universität Kaiserslautern, Germany
| | - Daniel Adam
- Department of Physics and Research Center OPTIMAS, Technische Universität Kaiserslautern, Germany
| | - Tobias Lausch
- Department of Physics and Research Center OPTIMAS, Technische Universität Kaiserslautern, Germany
| | - Nicolas Spethmann
- Department of Physics and Research Center OPTIMAS, Technische Universität Kaiserslautern, Germany
| | - Artur Widera
- Department of Physics and Research Center OPTIMAS, Technische Universität Kaiserslautern, Germany
- Graduate School Materials Science in Mainz, Gottlieb-Daimler-Strasse 47, 67663 Kaiserslautern, Germany
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23
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Sorting ultracold atoms in a three-dimensional optical lattice in a realization of Maxwell’s demon. Nature 2018; 561:83-87. [DOI: 10.1038/s41586-018-0458-7] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 07/16/2018] [Indexed: 11/08/2022]
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24
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Yan Y, Zhou Q. Yang Monopoles and Emergent Three-Dimensional Topological Defects in Interacting Bosons. PHYSICAL REVIEW LETTERS 2018; 120:235302. [PMID: 29932699 DOI: 10.1103/physrevlett.120.235302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Indexed: 06/08/2023]
Abstract
The Yang monopole as a zero-dimensional topological defect has been well established in multiple fields in physics. However, it remains an intriguing question to understand the interaction effects on Yang monopoles. Here, we show that the collective motion of many interacting bosons gives rise to exotic topological defects that are distinct from Yang monopoles seen by a single particle. Whereas interactions may distribute Yang monopoles in the parameter space or glue them to a single giant one of multiple charges, three-dimensional topological defects also arise from continuous manifolds of degenerate many-body eigenstates. Their projections in lower dimensions lead to knotted nodal lines and nodal rings. Our results suggest that ultracold bosonic atoms can be used to create emergent topological defects and directly measure topological invariants that are not easy to access in solids.
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Affiliation(s)
- Yangqian Yan
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47906, USA
| | - Qi Zhou
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47906, USA
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25
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Mistakidis S, Koutentakis G, Schmelcher P. Bosonic quantum dynamics following a linear interaction quench in finite optical lattices of unit filling. Chem Phys 2018. [DOI: 10.1016/j.chemphys.2017.11.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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26
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Lester BJ, Lin Y, Brown MO, Kaufman AM, Ball RJ, Knill E, Rey AM, Regal CA. Measurement-Based Entanglement of Noninteracting Bosonic Atoms. PHYSICAL REVIEW LETTERS 2018; 120:193602. [PMID: 29799233 DOI: 10.1103/physrevlett.120.193602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Indexed: 06/08/2023]
Abstract
We demonstrate the ability to extract a spin-entangled state of two neutral atoms via postselection based on a measurement of their spatial configuration. Typically, entangled states of neutral atoms are engineered via atom-atom interactions. In contrast, in our Letter, we use Hong-Ou-Mandel interference to postselect a spin-singlet state after overlapping two atoms in distinct spin states on an effective beam splitter. We verify the presence of entanglement and determine a bound on the postselected fidelity of a spin-singlet state of (0.62±0.03). The experiment has direct analogy to creating polarization entanglement with single photons and hence demonstrates the potential to use protocols developed for photons to create complex quantum states with noninteracting atoms.
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Affiliation(s)
- Brian J Lester
- JILA, National Institute of Standards and Technology and University of Colorado, and Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - Yiheng Lin
- JILA, National Institute of Standards and Technology and University of Colorado, and Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - Mark O Brown
- JILA, National Institute of Standards and Technology and University of Colorado, and Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - Adam M Kaufman
- JILA, National Institute of Standards and Technology and University of Colorado, and Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - Randall J Ball
- JILA, National Institute of Standards and Technology and University of Colorado, and Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - Emanuel Knill
- National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA
- Center for Theory of Quantum Matter, University of Colorado, Boulder, Colorado 80309, USA
| | - Ana M Rey
- JILA, National Institute of Standards and Technology and University of Colorado, and Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
- Center for Theory of Quantum Matter, University of Colorado, Boulder, Colorado 80309, USA
| | - Cindy A Regal
- JILA, National Institute of Standards and Technology and University of Colorado, and Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
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27
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Ground-State Magnetization in Mixtures of a Few Ultra-Cold Fermions in One-Dimensional Traps. CONDENSED MATTER 2018. [DOI: 10.3390/condmat3010007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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28
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An FA, Meier EJ, Ang'ong'a J, Gadway B. Correlated Dynamics in a Synthetic Lattice of Momentum States. PHYSICAL REVIEW LETTERS 2018; 120:040407. [PMID: 29437415 DOI: 10.1103/physrevlett.120.040407] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 08/09/2017] [Indexed: 06/08/2023]
Abstract
We study the influence of atomic interactions on quantum simulations in momentum-space lattices (MSLs), where driven transitions between discrete momentum states mimic transport between sites of a synthetic lattice. Low-energy atomic collisions, which are short ranged in real space, relate to nearly infinite-ranged interactions in momentum space. However, the added exchange energy between atoms in distinguishable momentum states leads to an effectively attractive, finite-ranged interaction between atoms in momentum space. In this Letter, we observe the onset of self-trapping driven by such interactions in a momentum-space double well, paving the way for more complex many-body studies in tailored MSLs. We consider the types of phenomena that may result from these interactions, including the formation of chiral solitons in zigzag flux lattices.
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Affiliation(s)
- Fangzhao Alex An
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801-3080, USA
| | - Eric J Meier
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801-3080, USA
| | - Jackson Ang'ong'a
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801-3080, USA
| | - Bryce Gadway
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801-3080, USA
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29
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Roos CF, Alberti A, Meschede D, Hauke P, Häffner H. Revealing Quantum Statistics with a Pair of Distant Atoms. PHYSICAL REVIEW LETTERS 2017; 119:160401. [PMID: 29099213 DOI: 10.1103/physrevlett.119.160401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Indexed: 06/07/2023]
Abstract
Quantum statistics have a profound impact on the properties of systems composed of identical particles. At the most elementary level, Bose and Fermi quantum statistics differ in the exchange phase, either 0 or π, which the wave function acquires when two identical particles are exchanged. In this Letter, we demonstrate that the exchange phase can be directly probed with a pair of massive particles by physically exchanging their positions. We present two protocols where the particles always remain spatially well separated, thus ensuring that the exchange contribution to their interaction energy is negligible and that the detected signal can only be attributed to the exchange symmetry of the wave function. We discuss possible implementations with a pair of trapped atoms or ions.
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Affiliation(s)
- C F Roos
- Institut für Quantenoptik und Quanteninformation der Österreichischen Akademie der Wissenschaften, Otto-Hittmair-Platz 1, A-6020 Innsbruck, Austria
| | - A Alberti
- Institut für Angewandte Physik der Universität Bonn, Wegelerstraße 8, 53115 Bonn, Germany
| | - D Meschede
- Institut für Angewandte Physik der Universität Bonn, Wegelerstraße 8, 53115 Bonn, Germany
| | - P Hauke
- Institut für Quantenoptik und Quanteninformation der Österreichischen Akademie der Wissenschaften, Otto-Hittmair-Platz 1, A-6020 Innsbruck, Austria
- Institut für Theoretische Physik, Universität Innsbruck, Technikerstraße 21a, 6020 Innsbruck, Austria
- Kirchhoff-Institut für Physik, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 227, 69120 Heidelberg, Germany
| | - H Häffner
- Department of Physics, University of California, Berkeley, California 94720, USA
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30
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Zeng Y, Xu P, He X, Liu Y, Liu M, Wang J, Papoular DJ, Shlyapnikov GV, Zhan M. Entangling Two Individual Atoms of Different Isotopes via Rydberg Blockade. PHYSICAL REVIEW LETTERS 2017; 119:160502. [PMID: 29099205 DOI: 10.1103/physrevlett.119.160502] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Indexed: 06/07/2023]
Abstract
We report on the first experimental realization of the controlled-not (cnot) quantum gate and entanglement for two individual atoms of different isotopes and demonstrate a negligible cross talk between two atom qubits. The experiment is based on a strong Rydberg blockade for ^{87}Rb and ^{85}Rb atoms confined in two single-atom optical traps separated by 3.8 μm. The raw fidelities of the cnot gate and entanglement are 0.73±0.01 and 0.59±0.03, respectively, without any corrections for atom loss or trace loss. Our work has applications for simulations of many-body systems with multispecies interactions, for quantum computing, and for quantum metrology.
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Affiliation(s)
- Yong Zeng
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences-Wuhan National Laboratory for Optoelectronics, Wuhan 430071, China
- Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Peng Xu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences-Wuhan National Laboratory for Optoelectronics, Wuhan 430071, China
- Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Xiaodong He
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences-Wuhan National Laboratory for Optoelectronics, Wuhan 430071, China
- Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Yangyang Liu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences-Wuhan National Laboratory for Optoelectronics, Wuhan 430071, China
- Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Min Liu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences-Wuhan National Laboratory for Optoelectronics, Wuhan 430071, China
- Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Jin Wang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences-Wuhan National Laboratory for Optoelectronics, Wuhan 430071, China
- Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071, China
| | - D J Papoular
- LPTM, UMR8089 of CNRS and Université de Cergy-Pontoise, F-95302 Cergy-Pontoise, France
| | - G V Shlyapnikov
- LPTMS, UMR8626 of CNRS and Université Paris-Sud, F-91405 Orsay, France
- SPEC, CEA & CNRS, Université Paris-Saclay, CEA Saclay, F-91191 Gif-sur-Yvette, France
- Russian Quantum Center, Novaya Street, Skolkovo, Moscow Region R-143025, Russia
- Van der Waals-Zeeman Institute, Institute of Physics, University of Amsterdam, The Netherlands
| | - Mingsheng Zhan
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences-Wuhan National Laboratory for Optoelectronics, Wuhan 430071, China
- Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071, China
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31
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Welte S, Hacker B, Daiss S, Ritter S, Rempe G. Cavity Carving of Atomic Bell States. PHYSICAL REVIEW LETTERS 2017; 118:210503. [PMID: 28598645 DOI: 10.1103/physrevlett.118.210503] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Indexed: 06/07/2023]
Abstract
We demonstrate entanglement generation of two neutral atoms trapped inside an optical cavity. Entanglement is created from initially separable two-atom states through carving with weak photon pulses reflected from the cavity. A polarization rotation of the photons heralds the entanglement. We show the successful implementation of two different protocols and the generation of all four Bell states with a maximum fidelity of (90±2)%. The protocol works for any distance between cavity-coupled atoms, and no individual addressing is required. Our result constitutes an important step towards applications in quantum networks, e.g., for entanglement swapping in a quantum repeater.
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Affiliation(s)
- Stephan Welte
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany
| | - Bastian Hacker
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany
| | - Severin Daiss
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany
| | - Stephan Ritter
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany
| | - Gerhard Rempe
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany
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32
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Universality of Schmidt decomposition and particle identity. Sci Rep 2017; 7:44675. [PMID: 28333163 PMCID: PMC5363071 DOI: 10.1038/srep44675] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 02/03/2017] [Indexed: 11/25/2022] Open
Abstract
Schmidt decomposition is a widely employed tool of quantum theory which plays a key role for distinguishable particles in scenarios such as entanglement characterization, theory of measurement and state purification. Yet, its formulation for identical particles remains controversial, jeopardizing its application to analyze general many-body quantum systems. Here we prove, using a newly developed approach, a universal Schmidt decomposition which allows faithful quantification of the physical entanglement due to the identity of particles. We find that it is affected by single-particle measurement localization and state overlap. We study paradigmatic two-particle systems where identical qubits and qutrits are located in the same place or in separated places. For the case of two qutrits in the same place, we show that their entanglement behavior, whose physical interpretation is given, differs from that obtained before by different methods. Our results are generalizable to multiparticle systems and open the way for further developments in quantum information processing exploiting particle identity as a resource.
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33
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Endres M, Bernien H, Keesling A, Levine H, Anschuetz ER, Krajenbrink A, Senko C, Vuletic V, Greiner M, Lukin MD. Atom-by-atom assembly of defect-free one-dimensional cold atom arrays. Science 2016; 354:1024-1027. [PMID: 27811284 DOI: 10.1126/science.aah3752] [Citation(s) in RCA: 179] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 10/17/2016] [Indexed: 11/02/2022]
Abstract
The realization of large-scale fully controllable quantum systems is an exciting frontier in modern physical science. We use atom-by-atom assembly to implement a platform for the deterministic preparation of regular one-dimensional arrays of individually controlled cold atoms. In our approach, a measurement and feedback procedure eliminates the entropy associated with probabilistic trap occupation and results in defect-free arrays of more than 50 atoms in less than 400 milliseconds. The technique is based on fast, real-time control of 100 optical tweezers, which we use to arrange atoms in desired geometric patterns and to maintain these configurations by replacing lost atoms with surplus atoms from a reservoir. This bottom-up approach may enable controlled engineering of scalable many-body systems for quantum information processing, quantum simulations, and precision measurements.
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Affiliation(s)
- Manuel Endres
- Department of Physics, Harvard University, Cambridge, MA 02138, USA. .,Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, CA 91125, USA
| | - Hannes Bernien
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
| | | | - Harry Levine
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
| | - Eric R Anschuetz
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
| | | | - Crystal Senko
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
| | - Vladan Vuletic
- Department of Physics and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Markus Greiner
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
| | - Mikhail D Lukin
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
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34
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Kim H, Lee W, Lee HG, Jo H, Song Y, Ahn J. In situ single-atom array synthesis using dynamic holographic optical tweezers. Nat Commun 2016; 7:13317. [PMID: 27796372 PMCID: PMC5095563 DOI: 10.1038/ncomms13317] [Citation(s) in RCA: 128] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 09/22/2016] [Indexed: 11/17/2022] Open
Abstract
Establishing a reliable method to form scalable neutral-atom platforms is an essential cornerstone for quantum computation, quantum simulation and quantum many-body physics. Here we demonstrate a real-time transport of single atoms using holographic microtraps controlled by a liquid-crystal spatial light modulator. For this, an analytical design approach to flicker-free microtrap movement is devised and cold rubidium atoms are simultaneously rearranged with 2N motional degrees of freedom, representing unprecedented space controllability. We also accomplish an in situ feedback control for single-atom rearrangements with the high success rate of 99% for up to 10 μm translation. We hope this proof-of-principle demonstration of high-fidelity atom-array preparations will be useful for deterministic loading of N single atoms, especially on arbitrary lattice locations, and also for real-time qubit shuttling in high-dimensional quantum computing architectures. It would be desirable to have a reliable and scalable method to manipulate neutral-atoms for the creation of controllable quantum systems. Here the authors demonstrate real-time transport of single rubidium atoms in holographic microtraps controlled by liquid-crystal spatial light modulators.
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Affiliation(s)
- Hyosub Kim
- Department of Physics, KAIST, Daejeon 305-701, Korea
| | - Woojun Lee
- Department of Physics, KAIST, Daejeon 305-701, Korea
| | - Han-Gyeol Lee
- Department of Physics, KAIST, Daejeon 305-701, Korea
| | - Hanlae Jo
- Department of Physics, KAIST, Daejeon 305-701, Korea
| | - Yunheung Song
- Department of Physics, KAIST, Daejeon 305-701, Korea
| | - Jaewook Ahn
- Department of Physics, KAIST, Daejeon 305-701, Korea
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35
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Sørensen JJWH, Pedersen MK, Munch M, Haikka P, Jensen JH, Planke T, Andreasen MG, Gajdacz M, Mølmer K, Lieberoth A, Sherson JF. Exploring the quantum speed limit with computer games. Nature 2016; 532:210-3. [PMID: 27075097 DOI: 10.1038/nature17620] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 02/12/2016] [Indexed: 12/11/2022]
Abstract
Humans routinely solve problems of immense computational complexity by intuitively forming simple, low-dimensional heuristic strategies. Citizen science (or crowd sourcing) is a way of exploiting this ability by presenting scientific research problems to non-experts. 'Gamification'--the application of game elements in a non-game context--is an effective tool with which to enable citizen scientists to provide solutions to research problems. The citizen science games Foldit, EteRNA and EyeWire have been used successfully to study protein and RNA folding and neuron mapping, but so far gamification has not been applied to problems in quantum physics. Here we report on Quantum Moves, an online platform gamifying optimization problems in quantum physics. We show that human players are able to find solutions to difficult problems associated with the task of quantum computing. Players succeed where purely numerical optimization fails, and analyses of their solutions provide insights into the problem of optimization of a more profound and general nature. Using player strategies, we have thus developed a few-parameter heuristic optimization method that efficiently outperforms the most prominent established numerical methods. The numerical complexity associated with time-optimal solutions increases for shorter process durations. To understand this better, we produced a low-dimensional rendering of the optimization landscape. This rendering reveals why traditional optimization methods fail near the quantum speed limit (that is, the shortest process duration with perfect fidelity). Combined analyses of optimization landscapes and heuristic solution strategies may benefit wider classes of optimization problems in quantum physics and beyond.
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Affiliation(s)
| | | | - Michael Munch
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - Pinja Haikka
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | | | - Tilo Planke
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | | | - Miroslav Gajdacz
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - Klaus Mølmer
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - Andreas Lieberoth
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - Jacob F Sherson
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
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36
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Tamura H, Unakami T, He J, Miyamoto Y, Nakagawa K. Highly uniform holographic microtrap arrays for single atom trapping using a feedback optimization of in-trap fluorescence measurements. OPTICS EXPRESS 2016; 24:8132-8141. [PMID: 27137252 DOI: 10.1364/oe.24.008132] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We report on the novel optimization method to realize highly uniform microtrap arrays for single atom trapping with a spatial light modulator (SLM). This method consists of two iterative feedback loops with the measurements of both diffracted light intensities and in-trap fluorescence intensities from each microtrap. By applying this method to the single 87Rb atom trapping, we can reduce the variance of trap depths from 20.8% to 1.7% for 4 × 4 square arrays and less than 4% for various arrays with up to 62 sites. The detection error of individual single atoms is also reduced from 1.7% to 0.0054% on average.
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37
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Quantum entanglement of identical particles by standard information-theoretic notions. Sci Rep 2016; 6:20603. [PMID: 26857475 PMCID: PMC4746635 DOI: 10.1038/srep20603] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 01/07/2016] [Indexed: 11/23/2022] Open
Abstract
Quantum entanglement of identical particles is essential in quantum information theory. Yet, its correct determination remains an open issue hindering the general understanding and exploitation of many-particle systems. Operator-based methods have been developed that attempt to overcome the issue. Here we introduce a state-based method which, as second quantization, does not label identical particles and presents conceptual and technical advances compared to the previous ones. It establishes the quantitative role played by arbitrary wave function overlaps, local measurements and particle nature (bosons or fermions) in assessing entanglement by notions commonly used in quantum information theory for distinguishable particles, like partial trace. Our approach furthermore shows that bringing identical particles into the same spatial location functions as an entangling gate, providing fundamental theoretical support to recent experimental observations with ultracold atoms. These results pave the way to set and interpret experiments for utilizing quantum correlations in realistic scenarios where overlap of particles can count, as in Bose-Einstein condensates, quantum dots and biological molecular aggregates.
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