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Jadot B, Mortemousque PA, Chanrion E, Thiney V, Ludwig A, Wieck AD, Urdampilleta M, Bäuerle C, Meunier T. Distant spin entanglement via fast and coherent electron shuttling. NATURE NANOTECHNOLOGY 2021; 16:570-575. [PMID: 33589811 DOI: 10.1038/s41565-021-00846-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 01/06/2021] [Indexed: 06/12/2023]
Abstract
In the quest for large-scale quantum computing, networked quantum computers offer a natural path towards scalability. While recent experiments have demonstrated nearest neighbour entanglement for electron spin qubits in semiconductors, on-chip long-distance entanglement could bring more versatility to connect quantum core units. Here, we employ the moving trapping potential of a surface acoustic wave to realize the controlled and coherent transfer of a pair of entangled electron spins between two distant quantum dots. The subsequent electron displacement induces coherent spin rotations, which drives spin quantum interferences. We observe high-contrast interference as a signature of the preservation of the entanglement all along the displacement procedure, which includes a separation of the two spins by a distance of 6 μm. This work opens the route towards fast on-chip deterministic interconnection of remote quantum bits in semiconductor quantum circuits.
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Affiliation(s)
- Baptiste Jadot
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, Grenoble, France.
| | | | - Emmanuel Chanrion
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, Grenoble, France
| | - Vivien Thiney
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, Grenoble, France
| | - Arne Ludwig
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Bochum, Germany
| | - Andreas D Wieck
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Bochum, Germany
| | - Matias Urdampilleta
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, Grenoble, France
| | - Christopher Bäuerle
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, Grenoble, France
| | - Tristan Meunier
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, Grenoble, France.
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2
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Filippone M, Marguerite A, Le Hur K, Fève G, Mora C. Phase-Coherent Dynamics of Quantum Devices with Local Interactions. ENTROPY (BASEL, SWITZERLAND) 2020; 22:E847. [PMID: 33286618 PMCID: PMC7517448 DOI: 10.3390/e22080847] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/21/2020] [Accepted: 07/02/2020] [Indexed: 11/16/2022]
Abstract
This review illustrates how Local Fermi Liquid (LFL) theories describe the strongly correlated and coherent low-energy dynamics of quantum dot devices. This approach consists in an effective elastic scattering theory, accounting exactly for strong correlations. Here, we focus on the mesoscopic capacitor and recent experiments achieving a Coulomb-induced quantum state transfer. Extending to out-of-equilibrium regimes, aimed at triggered single electron emission, we illustrate how inelastic effects become crucial, requiring approaches beyond LFLs, shedding new light on past experimental data by showing clear interaction effects in the dynamics of mesoscopic capacitors.
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Affiliation(s)
- Michele Filippone
- Department of Quantum Matter Physics, University of Geneva 24 Quai Ernest-Ansermet, CH-1211 Geneva, Switzerland
| | - Arthur Marguerite
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel;
| | - Karyn Le Hur
- CPHT, CNRS, Institut Polytechnique de Paris, Route de Saclay, 91128 Palaiseau, France;
| | - Gwendal Fève
- Laboratoire de Physique de l’Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, F-75005 Paris, France;
| | - Christophe Mora
- Laboratoire Matériaux et Phénomènes Quantiques, CNRS, Université de Paris, F-75013 Paris, France;
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Zhao X, Hu X. Toward high-fidelity coherent electron spin transport in a GaAs double quantum dot. Sci Rep 2018; 8:13968. [PMID: 30228299 PMCID: PMC6143546 DOI: 10.1038/s41598-018-31879-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 08/14/2018] [Indexed: 11/18/2022] Open
Abstract
In this paper, we investigate how to achieve high-fidelity electron spin transport in a GaAs double quantum dot. Our study examines fidelity loss in spin transport from multiple perspectives. We first study incoherent fidelity loss due to hyperfine and spin-orbit interaction. We calculate fidelity loss due to the random Overhauser field from hyperfine interaction, and spin relaxation rate due to spin-orbit interaction in a wide range of experimental parameters with a focus on the occurrence of spin hot spots. A safe parameter regime is identified in order to avoid these spin hot spots. We then analyze systematic errors due to non-adiabatic transitions in the Landau-Zener process of sweeping the interdot detuning, and propose a scheme to take advantage of possible Landau-Zener-Stückelberg interference to achieve high-fidelity spin transport at a higher speed. At last, we study another systematic error caused by the correction to the electron g-factor from the double dot potential, which can lead to a notable phase error. In all, our results should provide a useful guidance for future experiments on coherent electron spin transport.
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Affiliation(s)
- Xinyu Zhao
- Department of Physics, University at Buffalo, SUNY, Buffalo, New York, 14260-1500, USA
| | - Xuedong Hu
- Department of Physics, University at Buffalo, SUNY, Buffalo, New York, 14260-1500, USA.
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Bäuerle C, Christian Glattli D, Meunier T, Portier F, Roche P, Roulleau P, Takada S, Waintal X. Coherent control of single electrons: a review of current progress. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2018; 81:056503. [PMID: 29355831 DOI: 10.1088/1361-6633/aaa98a] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In this report we review the present state of the art of the control of propagating quantum states at the single-electron level and its potential application to quantum information processing. We give an overview of the different approaches that have been developed over the last few years in order to gain full control over a propagating single-electron in a solid-state system. After a brief introduction of the basic concepts, we present experiments on flying qubit circuits for ensemble of electrons measured in the low frequency (DC) limit. We then present the basic ingredients necessary to realise such experiments at the single-electron level. This includes a review of the various single-electron sources that have been developed over the last years and which are compatible with integrated single-electron circuits. This is followed by a review of recent key experiments on electron quantum optics with single electrons. Finally we will present recent developments in the new physics that has emerged using ultrashort voltage pulses. We conclude our review with an outlook and future challenges in the field.
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Affiliation(s)
- Christopher Bäuerle
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France
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5
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Flentje H, Mortemousque PA, Thalineau R, Ludwig A, Wieck AD, Bäuerle C, Meunier T. Coherent long-distance displacement of individual electron spins. Nat Commun 2017; 8:501. [PMID: 28894092 PMCID: PMC5593884 DOI: 10.1038/s41467-017-00534-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 07/06/2017] [Indexed: 11/16/2022] Open
Abstract
Controlling nanocircuits at the single electron spin level is a possible route for large-scale quantum information processing. In this context, individual electron spins have been identified as versatile quantum information carriers to interconnect different nodes of a spin-based semiconductor quantum circuit. Despite extensive experimental efforts to control the electron displacement over long distances, maintaining electron spin coherence after transfer remained elusive up to now. Here we demonstrate that individual electron spins can be displaced coherently over a distance of 5 µm. This displacement is realized on a closed path made of three tunnel-coupled lateral quantum dots at a speed approaching 100 ms−1. We find that the spin coherence length is eight times longer than expected from the electron spin coherence without displacement, pointing at a process similar to motional narrowing observed in nuclear magnetic resonance experiments. The demonstrated coherent displacement will open the route towards long-range interaction between distant spin qubits. The spin states of electrons in quantum dots have well-established potential for use as qubits but some proposed developments require the ability to move the quantum spin state across a larger device. Here, the authors experimentally demonstrate coherent shuttling of spins in a ring of three dots.
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Affiliation(s)
- H Flentje
- University of Grenoble Alpes, Institut NEEL, F-38042, Grenoble, France.,CNRS, Institut NEEL, F-38042, Grenoble, France
| | - P-A Mortemousque
- University of Grenoble Alpes, Institut NEEL, F-38042, Grenoble, France.,CNRS, Institut NEEL, F-38042, Grenoble, France
| | - R Thalineau
- University of Grenoble Alpes, Institut NEEL, F-38042, Grenoble, France.,CNRS, Institut NEEL, F-38042, Grenoble, France
| | - A Ludwig
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraße 150, D-44780, Bochum, Germany
| | - A D Wieck
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraße 150, D-44780, Bochum, Germany
| | - C Bäuerle
- University of Grenoble Alpes, Institut NEEL, F-38042, Grenoble, France.,CNRS, Institut NEEL, F-38042, Grenoble, France
| | - T Meunier
- University of Grenoble Alpes, Institut NEEL, F-38042, Grenoble, France. .,CNRS, Institut NEEL, F-38042, Grenoble, France.
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Bertrand B, Hermelin S, Takada S, Yamamoto M, Tarucha S, Ludwig A, Wieck AD, Bäuerle C, Meunier T. Fast spin information transfer between distant quantum dots using individual electrons. NATURE NANOTECHNOLOGY 2016; 11:672-676. [PMID: 27240417 DOI: 10.1038/nnano.2016.82] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 04/14/2016] [Indexed: 06/05/2023]
Abstract
Transporting ensembles of electrons over long distances without losing their spin polarization is an important benchmark for spintronic devices. It usually requires injecting and probing spin-polarized electrons in conduction channels using ferromagnetic contacts or optical excitation. In parallel with this development, important efforts have been dedicated to achieving control of nanocircuits at the single-electron level. The detection and coherent manipulation of the spin of a single electron trapped in a quantum dot are now well established. Combined with the recently demonstrated control of the displacement of individual electrons between two distant quantum dots, these achievements allow the possibility of realizing spintronic protocols at the single-electron level. Here, we demonstrate that spin information carried by one or two electrons can be transferred between two quantum dots separated by a distance of 4 μm with a classical fidelity of 65%. We show that at present it is limited by spin flips occurring during the transfer procedure before and after electron displacement. Being able to encode and control information in the spin degree of freedom of a single electron while it is being transferred over distances of a few micrometres on nanosecond timescales will pave the way towards 'quantum spintronics' devices, which could be used to implement large-scale spin-based quantum information processing.
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Affiliation(s)
- B Bertrand
- Université Grenoble Alpes, Institut NEEL, F-38042 Grenoble, France
- CNRS, Institut NEEL, F-38042 Grenoble, France
| | - S Hermelin
- Université Grenoble Alpes, Institut NEEL, F-38042 Grenoble, France
- CNRS, Institut NEEL, F-38042 Grenoble, France
| | - S Takada
- Université Grenoble Alpes, Institut NEEL, F-38042 Grenoble, France
- CNRS, Institut NEEL, F-38042 Grenoble, France
- Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan
| | - M Yamamoto
- Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan
- PRESTO-JST, Kawaguchi-shi, Saitama 331-0012, Japan
| | - S Tarucha
- Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan
- RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako-Shi, Saitama 31-0198, Japan
| | - A Ludwig
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - A D Wieck
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - C Bäuerle
- Université Grenoble Alpes, Institut NEEL, F-38042 Grenoble, France
- CNRS, Institut NEEL, F-38042 Grenoble, France
| | - T Meunier
- Université Grenoble Alpes, Institut NEEL, F-38042 Grenoble, France
- CNRS, Institut NEEL, F-38042 Grenoble, France
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