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Basso Basset F, Rota MB, Schimpf C, Tedeschi D, Zeuner KD, Covre da Silva SF, Reindl M, Zwiller V, Jöns KD, Rastelli A, Trotta R. Entanglement Swapping with Photons Generated on Demand by a Quantum Dot. Phys Rev Lett 2019; 123:160501. [PMID: 31702339 DOI: 10.1103/physrevlett.123.160501] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Indexed: 06/10/2023]
Abstract
Photonic entanglement swapping, the procedure of entangling photons without any direct interaction, is a fundamental test of quantum mechanics and an essential resource to the realization of quantum networks. Probabilistic sources of nonclassical light were used for seminal demonstration of entanglement swapping, but applications in quantum technologies demand push-button operation requiring single quantum emitters. This, however, turned out to be an extraordinary challenge due to the stringent prerequisites on the efficiency and purity of the generation of entangled states. Here we show a proof-of-concept demonstration of all-photonic entanglement swapping with pairs of polarization-entangled photons generated on demand by a GaAs quantum dot without spectral and temporal filtering. Moreover, we develop a theoretical model that quantitatively reproduces the experimental data and provides insights on the critical figures of merit for the performance of the swapping operation. Our theoretical analysis also indicates how to improve state-of-the-art entangled-photon sources to meet the requirements needed for implementation of quantum dots in long-distance quantum communication protocols.
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Affiliation(s)
- F Basso Basset
- Department of Physics, Sapienza University of Rome, 00185 Rome, Italy
| | - M B Rota
- Department of Physics, Sapienza University of Rome, 00185 Rome, Italy
| | - C Schimpf
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University, 4040 Linz, Austria
| | - D Tedeschi
- Department of Physics, Sapienza University of Rome, 00185 Rome, Italy
| | - K D Zeuner
- Department of Applied Physics, Royal Institute of Technology, 106 91 Stockholm, Sweden
| | - S F Covre da Silva
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University, 4040 Linz, Austria
| | - M Reindl
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University, 4040 Linz, Austria
| | - V Zwiller
- Department of Applied Physics, Royal Institute of Technology, 106 91 Stockholm, Sweden
| | - K D Jöns
- Department of Applied Physics, Royal Institute of Technology, 106 91 Stockholm, Sweden
| | - A Rastelli
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University, 4040 Linz, Austria
| | - R Trotta
- Department of Physics, Sapienza University of Rome, 00185 Rome, Italy
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Assali S, Lähnemann J, Vu TTT, Jöns KD, Gagliano L, Verheijen MA, Akopian N, Bakkers EPAM, Haverkort JEM. Crystal Phase Quantum Well Emission with Digital Control. Nano Lett 2017; 17:6062-6068. [PMID: 28892396 PMCID: PMC5642001 DOI: 10.1021/acs.nanolett.7b02489] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 09/06/2017] [Indexed: 05/31/2023]
Abstract
One of the major challenges in the growth of quantum well and quantum dot heterostructures is the realization of atomically sharp interfaces. Nanowires provide a new opportunity to engineer the band structure as they facilitate the controlled switching of the crystal structure between the zinc-blende (ZB) and wurtzite (WZ) phases. Such a crystal phase switching results in the formation of crystal phase quantum wells (CPQWs) and quantum dots (CPQDs). For GaP CPQWs, the inherent electric fields due to the discontinuity of the spontaneous polarization at the WZ/ZB junctions lead to the confinement of both types of charge carriers at the opposite interfaces of the WZ/ZB/WZ structure. This confinement leads to a novel type of transition across a ZB flat plate barrier. Here, we show digital tuning of the visible emission of WZ/ZB/WZ CPQWs in a GaP nanowire by changing the thickness of the ZB barrier. The energy spacing between the sharp emission lines is uniform and is defined by the addition of single ZB monolayers. The controlled growth of identical quantum wells with atomically flat interfaces at predefined positions featuring digitally tunable discrete emission energies may provide a new route to further advance entangled photons in solid state quantum systems.
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Affiliation(s)
- S. Assali
- Department
of Applied Physics, Eindhoven University
of Technology, 5600 MB, Eindhoven, The Netherlands
| | - J. Lähnemann
- Paul-Drude-Institut
für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin, Germany
| | - T. T. T. Vu
- Department
of Applied Physics, Eindhoven University
of Technology, 5600 MB, Eindhoven, The Netherlands
| | - K. D. Jöns
- Kavli
Institute of Nanoscience, Delft University
of Technology, 2600 GA, Delft, The Netherlands
| | - L. Gagliano
- Department
of Applied Physics, Eindhoven University
of Technology, 5600 MB, Eindhoven, The Netherlands
| | - M. A. Verheijen
- Department
of Applied Physics, Eindhoven University
of Technology, 5600 MB, Eindhoven, The Netherlands
- Philips
Innovation Services Eindhoven, High Tech Campus 11, 5656 AE, Eindhoven, The
Netherlands
| | - N. Akopian
- Department
of Applied Physics, Eindhoven University
of Technology, 5600 MB, Eindhoven, The Netherlands
- Kavli
Institute of Nanoscience, Delft University
of Technology, 2600 GA, Delft, The Netherlands
| | - E. P. A. M. Bakkers
- Department
of Applied Physics, Eindhoven University
of Technology, 5600 MB, Eindhoven, The Netherlands
- Kavli
Institute of Nanoscience, Delft University
of Technology, 2600 GA, Delft, The Netherlands
| | - J. E. M. Haverkort
- Department
of Applied Physics, Eindhoven University
of Technology, 5600 MB, Eindhoven, The Netherlands
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Jöns KD, Hafenbrak R, Singh R, Ding F, Plumhof JD, Rastelli A, Schmidt OG, Bester G, Michler P. Dependence of the redshifted and blueshifted photoluminescence spectra of single In(x)Ga(1-x)As/GaAs quantum dots on the applied uniaxial stress. Phys Rev Lett 2011; 107:217402. [PMID: 22181923 DOI: 10.1103/physrevlett.107.217402] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Indexed: 05/28/2023]
Abstract
We apply external uniaxial stress to tailor the optical properties of In(x)Ga(1-x)As/GaAs quantum dots. Unexpectedly, the emission energy of single quantum dots controllably shifts to both higher and lower energies under tensile strain. Theoretical calculations using a million atom empirical pseudopotential many-body method indicate that the shifting direction and magnitude depend on the lateral extension and more interestingly on the gallium content of the quantum dots. Our experimental results are in good agreement with the underlying theory.
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Affiliation(s)
- K D Jöns
- Institut für Halbleiteroptik und Funktionelle Grenzflächen, University of Stuttgart, Germany.
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