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Millington-Hotze P, Dyte HE, Manna S, Covre da Silva SF, Rastelli A, Chekhovich EA. Approaching a fully-polarized state of nuclear spins in a solid. Nat Commun 2024; 15:985. [PMID: 38307879 PMCID: PMC10837425 DOI: 10.1038/s41467-024-45364-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Accepted: 01/18/2024] [Indexed: 02/04/2024] Open
Abstract
Magnetic noise of atomic nuclear spins is a major source of decoherence in solid-state spin qubits. In theory, near-unity nuclear spin polarization can eliminate decoherence of the electron spin qubit, while turning the nuclei into a useful quantum information resource. However, achieving sufficiently high nuclear polarizations has remained an evasive goal. Here we implement a nuclear spin polarization protocol which combines strong optical pumping and fast electron tunneling. Nuclear polarizations well above 95% are generated in GaAs semiconductor quantum dots on a timescale of 1 minute. The technique is compatible with standard quantum dot device designs, where highly-polarized nuclear spins can simplify implementations of qubits and quantum memories, as well as offer a testbed for studies of many-body quantum dynamics and magnetism.
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Affiliation(s)
- Peter Millington-Hotze
- Department of Physics and Astronomy, University of Sheffield, Sheffield, S3 7RH, United Kingdom
| | - Harry E Dyte
- Department of Physics and Astronomy, University of Sheffield, Sheffield, S3 7RH, United Kingdom
| | - Santanu Manna
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University Linz, Altenberger Str. 69, Linz, 4040, Austria
- Department of Electrical Engineering, Indian Institute of Technology Delhi, New Delhi, 110016, India
| | - Saimon F Covre da Silva
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University Linz, Altenberger Str. 69, Linz, 4040, Austria
| | - Armando Rastelli
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University Linz, Altenberger Str. 69, Linz, 4040, Austria
| | - Evgeny A Chekhovich
- Department of Physics and Astronomy, University of Sheffield, Sheffield, S3 7RH, United Kingdom.
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2
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Carollo F. Non-Gaussian Dynamics of Quantum Fluctuations and Mean-Field Limit in Open Quantum Central Spin Systems. PHYSICAL REVIEW LETTERS 2023; 131:227102. [PMID: 38101340 DOI: 10.1103/physrevlett.131.227102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Revised: 08/10/2023] [Accepted: 11/01/2023] [Indexed: 12/17/2023]
Abstract
Central spin systems, in which a central spin is singled out and interacts nonlocally with several bath spins, are paradigmatic models for nitrogen-vacancy centers and quantum dots. They show complex emergent dynamics and stationary phenomena which, despite the collective nature of their interaction, are still largely not understood. Here, we derive exact results on the emergent behavior of open quantum central spin systems. The latter crucially depends on the scaling of the interaction strength with the bath size. For scalings with the inverse square root of the bath size (typical of one-to-many interactions), the system behaves, in the thermodynamic limit, as an open quantum Jaynes-Cummings model, whose bosonic mode encodes the quantum fluctuations of the bath spins. In this case, non-Gaussian correlations are dynamically generated and persist at stationarity. For scalings with the inverse bath size, the emergent dynamics is instead of mean-field type. Our Letter provides a fundamental understanding of the different dynamical regimes of central spin systems and a simple theory for efficiently exploring their nonequilibrium behavior. Our findings may become relevant for developing fully quantum descriptions of many-body solid-state devices and their applications.
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Affiliation(s)
- Federico Carollo
- Institut für Theoretische Physik, Universität Tübingen, Auf der Morgenstelle 14, 72076 Tübingen, Germany
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3
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Alodjants A, Zacharenko P, Tsarev D, Avdyushina A, Nikitina M, Khrennikov A, Boukhanovsky A. Random Lasers as Social Processes Simulators. ENTROPY (BASEL, SWITZERLAND) 2023; 25:1601. [PMID: 38136481 PMCID: PMC10742775 DOI: 10.3390/e25121601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 11/26/2023] [Accepted: 11/27/2023] [Indexed: 12/24/2023]
Abstract
In this work, we suggest a quantum-like simulator concept to study social processes related to the solution of NP-hard problems. The simulator is based on the solaser model recently proposed by us in the framework of information cascade growth and echo chamber formation in social network communities. The simulator is connected with the random laser approach that we examine in the A and D-class (superradiant) laser limits. Novel network-enforced cooperativity parameters of decision-making agents, which may be measured as a result of the solaser simulation, are introduced and justified for social systems. The innovation diffusion in complex networks is discussed as one of the possible impacts of our proposal.
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Affiliation(s)
- Alexander Alodjants
- Institute of Advansed Data Transfer Systems, ITMO University, 197101 St. Petersburg, Russia; (A.A.); (P.Z.); (D.T.); (A.A.); (M.N.)
- National Center for Cognitive Research, ITMO University, 197101 St. Petersburg, Russia;
| | - Peter Zacharenko
- Institute of Advansed Data Transfer Systems, ITMO University, 197101 St. Petersburg, Russia; (A.A.); (P.Z.); (D.T.); (A.A.); (M.N.)
| | - Dmitry Tsarev
- Institute of Advansed Data Transfer Systems, ITMO University, 197101 St. Petersburg, Russia; (A.A.); (P.Z.); (D.T.); (A.A.); (M.N.)
| | - Anna Avdyushina
- Institute of Advansed Data Transfer Systems, ITMO University, 197101 St. Petersburg, Russia; (A.A.); (P.Z.); (D.T.); (A.A.); (M.N.)
| | - Mariya Nikitina
- Institute of Advansed Data Transfer Systems, ITMO University, 197101 St. Petersburg, Russia; (A.A.); (P.Z.); (D.T.); (A.A.); (M.N.)
| | - Andrey Khrennikov
- International Center for Mathematical Modeling in Physics, Engineering, Economics, and Cognitive Science, Linnaeus University, S-35195 Vaxjo-Kalmar, Sweden
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Shumilin AV, Smirnov DS. Nuclear Spin Dynamics, Noise, Squeezing, and Entanglement in Box Model. PHYSICAL REVIEW LETTERS 2021; 126:216804. [PMID: 34114866 DOI: 10.1103/physrevlett.126.216804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 03/24/2021] [Accepted: 04/27/2021] [Indexed: 06/12/2023]
Abstract
We obtain a compact analytical solution for the nonlinear equation for the nuclear spin dynamics in the central spin box model in the limit of many nuclear spins. The total nuclear spin component along the external magnetic field is conserved and the two perpendicular components precess or oscillate depending on the electron spin polarization, with the frequency, determined by the nuclear spin polarization. As applications of our solution, we calculate the nuclear spin noise spectrum and describe the effects of nuclear spin squeezing and many body entanglement in the absence of a system excitation.
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Affiliation(s)
| | - D S Smirnov
- Ioffe Institute, 194021 St. Petersburg, Russia
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Arenz C, Rabitz H. Controlling Qubit Networks in Polynomial Time. PHYSICAL REVIEW LETTERS 2018; 120:220503. [PMID: 29906136 DOI: 10.1103/physrevlett.120.220503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Indexed: 06/08/2023]
Abstract
Future quantum devices often rely on favorable scaling with respect to the number of system components. To achieve desirable scaling, it is therefore crucial to implement unitary transformations in a time that scales at most polynomial in the number of qubits. We develop an upper bound for the minimum time required to implement a unitary transformation on a generic qubit network in which each of the qubits is subject to local time dependent controls. Based on the developed upper bound, the set of gates is characterized that can be implemented polynomially in time. Furthermore, we show how qubit systems can be concatenated through controllable two body interactions, making it possible to implement the gate set efficiently on the combined system. Finally, a system is identified for which the gate set can be implemented with fewer controls.
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Affiliation(s)
- Christian Arenz
- Frick Laboratory, Princeton University, Princeton, New Jersey 08544, USA
| | - Herschel Rabitz
- Frick Laboratory, Princeton University, Princeton, New Jersey 08544, USA
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Genway S, Li W, Ates C, Lanyon BP, Lesanovsky I. Generalized Dicke nonequilibrium dynamics in trapped ions. PHYSICAL REVIEW LETTERS 2014; 112:023603. [PMID: 24484012 DOI: 10.1103/physrevlett.112.023603] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Indexed: 06/03/2023]
Abstract
We explore trapped ions as a setting to investigate nonequilibrium phases in a generalized Dicke model of dissipative spins coupled to phonon modes. We find a rich dynamical phase diagram including superradiantlike regimes, dynamical phase coexistence, and phonon-lasing behavior. A particular advantage of trapped ions is that these phases and transitions among them can be probed in situ through fluorescence. We demonstrate that the main physical insights are captured by a minimal model and consider an experimental realization with Ca+ ions trapped in a linear Paul trap with a dressing scheme to create effective two-level systems with a tunable dissipation rate.
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Affiliation(s)
- Sam Genway
- School of Physics and Astronomy, The University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Weibin Li
- School of Physics and Astronomy, The University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Cenap Ates
- School of Physics and Astronomy, The University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Benjamin P Lanyon
- Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, Technikerstr. 21A, 6020 Innsbruck, Austria and Institut für Experimentalphysik, Universität Innsbruck,Technikerstr. 25, 6020 Innsbruck, Austria
| | - Igor Lesanovsky
- School of Physics and Astronomy, The University of Nottingham, Nottingham NG7 2RD, United Kingdom
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Chekhovich EA, Makhonin MN, Tartakovskii AI, Yacoby A, Bluhm H, Nowack KC, Vandersypen LMK. Nuclear spin effects in semiconductor quantum dots. NATURE MATERIALS 2013; 12:494-504. [PMID: 23695746 DOI: 10.1038/nmat3652] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Accepted: 04/12/2013] [Indexed: 06/02/2023]
Abstract
The interaction of an electronic spin with its nuclear environment, an issue known as the central spin problem, has been the subject of considerable attention due to its relevance for spin-based quantum computation using semiconductor quantum dots. Independent control of the nuclear spin bath using nuclear magnetic resonance techniques and dynamic nuclear polarization using the central spin itself offer unique possibilities for manipulating the nuclear bath with significant consequences for the coherence and controlled manipulation of the central spin. Here we review some of the recent optical and transport experiments that have explored this central spin problem using semiconductor quantum dots. We focus on the interaction between 10(4)-10(6) nuclear spins and a spin of a single electron or valence-band hole. We also review the experimental techniques as well as the key theoretical ideas and the implications for quantum information science.
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Affiliation(s)
- E A Chekhovich
- Department of Physics and Astronomy, University of Sheffield, Sheffield, UK
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Bienaimé T, Piovella N, Kaiser R. Controlled Dicke subradiance from a large cloud of two-level systems. PHYSICAL REVIEW LETTERS 2012; 108:123602. [PMID: 22540580 DOI: 10.1103/physrevlett.108.123602] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Indexed: 05/31/2023]
Abstract
Dicke superradiance has been observed in many systems and is based on constructive interferences between many scattered waves. The counterpart of this enhanced dynamics, subradiance, is a destructive interference effect leading to the partial trapping of light in the system. In contrast to the robust superradiance, subradiant states are fragile, and spurious decoherence phenomena hitherto obstructed the observation of such metastable states. We show that a dilute cloud of cold atoms is an ideal system to look for subradiance in free space and study various mechanisms to control this subradiance.
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Affiliation(s)
- Tom Bienaimé
- Université de Nice Sophia Antipolis, CNRS, Institut Non-Linéaire de Nice, UMR 7335, F-06560 Valbonne, France
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