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da Cruz AR, Flatté ME. Dissipationless Circulating Currents and Fringe Magnetic Fields Near a Single Spin Embedded in a Two-Dimensional Electron Gas. PHYSICAL REVIEW LETTERS 2023; 131:086301. [PMID: 37683147 DOI: 10.1103/physrevlett.131.086301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 02/21/2023] [Accepted: 05/26/2023] [Indexed: 09/10/2023]
Abstract
Theoretical calculations predict the anisotropic dissipationless circulating current induced by a spin defect in a two-dimensional electron gas. The shape and spatial extent of these dissipationless circulating currents depend dramatically on the relative strengths of spin-orbit fields with differing spatial symmetry, offering the potential to use an electric gate to manipulate nanoscale magnetic fields and couple magnetic defects. The spatial structure of the magnetic field produced by this current is calculated and provides a direct way to measure the spin-orbit fields of the host, as well as the defect spin orientation, e.g., through scanning nanoscale magnetometry.
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Affiliation(s)
- Adonai R da Cruz
- Department of Applied Physics, Eindhoven University of Technology, Eindhoven 5612 AZ, The Netherlands
| | - Michael E Flatté
- Department of Applied Physics, Eindhoven University of Technology, Eindhoven 5612 AZ, The Netherlands
- Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242, USA
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2
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McMillan SR, Harmon NJ, Flatté ME. Image of Dynamic Local Exchange Interactions in the dc Magnetoresistance of Spin-Polarized Current through a Dopant. PHYSICAL REVIEW LETTERS 2020; 125:257203. [PMID: 33416385 DOI: 10.1103/physrevlett.125.257203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 09/15/2020] [Accepted: 11/10/2020] [Indexed: 06/12/2023]
Abstract
We predict strong, dynamical effects in the dc magnetoresistance of current flowing from a spin-polarized electrical contact through a magnetic dopant in a nonmagnetic host. Using the stochastic Liouville formalism we calculate clearly defined resonances in the dc magnetoresistance when the applied magnetic field matches the exchange interaction with a nearby spin. At these resonances spin precession in the applied magnetic field is canceled by spin evolution in the exchange field, preserving a dynamic bottleneck for spin transport through the dopant. Similar features emerge when the dopant spin is coupled to nearby nuclei through the hyperfine interaction. These features provide a precise means of measuring exchange or hyperfine couplings between localized spins near a surface using spin-polarized scanning tunneling microscopy, without any ac electric or magnetic fields, even when the exchange or hyperfine energy is orders of magnitude smaller than the thermal energy.
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Affiliation(s)
- Stephen R McMillan
- Optical Science and Technology Center, and Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242, USA
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
| | - Nicholas J Harmon
- Optical Science and Technology Center, and Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242, USA
| | - Michael E Flatté
- Optical Science and Technology Center, and Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242, USA
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
- Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, Netherlands
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Smoleński T, Cywiński Ł, Kossacki P. Mechanisms of optical orientation of an individual Mn 2+ ion spin in a II-VI quantum dot. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:055303. [PMID: 29315081 DOI: 10.1088/1361-648x/aaa20c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We provide a theoretical description of the optical orientation of a single Mn2+ ion spin under quasi-resonant excitation demonstrated experimentally by Goryca et al (2009 Phys. Rev. Lett. 103 087401). We build and analyze a hierarchy of models by starting with the simplest assumptions (transfer of perfectly spin-polarized excitons from Mn-free dot to the other dot containing a single Mn2+ spin, followed by radiative recombination) and subsequently adding more features, such as spin relaxation of electrons and holes. Particular attention is paid to the role of the influx of the dark excitons and the process of biexciton formation, which are shown to contribute significantly to the orientation process in the quasi-resonant excitation case. Analyzed scenarios show how multiple features of the excitonic complexes in magnetically-doped quantum dots, such as the values of exchange integrals, spin relaxation times, etc, lead to a plethora of optical orientation processes, characterized by distinct dependencies on light polarization and laser intensity, and occurring on distinct timescales. Comparison with experimental data shows that the correct description of the optical orientation mechanism requires taking into account Mn2+ spin-flip processes occurring not only when the exciton is already in the orbital ground state of the light-emitting dot, but also those that happen during the exciton transfer from high-energy states to the ground state. Inspired by the experimental results on energy relaxation of electrons and holes in nonmagnetic dots, we focus on the process of biexciton creation allowed by mutual spin-flip of an electron and the Mn2+ spin, and we show that by including it in the model, we obtain good qualitative and quantitative agreement with the experimental data on quasi-resonantly driven Mn2+ spin orientation.
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Affiliation(s)
- T Smoleński
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
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Kobak J, Smoleński T, Goryca M, Papaj M, Gietka K, Bogucki A, Koperski M, Rousset JG, Suffczyński J, Janik E, Nawrocki M, Golnik A, Kossacki P, Pacuski W. Designing quantum dots for solotronics. Nat Commun 2015; 5:3191. [PMID: 24463946 PMCID: PMC3916836 DOI: 10.1038/ncomms4191] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Accepted: 01/02/2014] [Indexed: 01/28/2023] Open
Abstract
Solotronics, optoelectronics based on solitary dopants, is an emerging field of research and technology reaching the ultimate limit of miniaturization. It aims at exploiting quantum properties of individual ions or defects embedded in a semiconductor matrix. It has already been shown that optical control of a magnetic ion spin is feasible using the carriers confined in a quantum dot. However, a serious obstacle was the quenching of the exciton luminescence by magnetic impurities. Here we show, by photoluminescence studies on thus-far-unexplored individual CdTe dots with a single cobalt ion and CdSe dots with a single manganese ion, that even if energetically allowed, nonradiative exciton recombination through single-magnetic-ion intra-ionic transitions is negligible in such zero-dimensional structures. This opens solotronics for a wide range of as yet unconsidered systems. On the basis of results of our single-spin relaxation experiments and on the material trends, we identify optimal magnetic-ion quantum dot systems for implementation of a single-ion-based spin memory. Single-atom dopants embedded in a semiconductor matrix are of potential use for optical, spintronics as well as information storage applications. Here, Kobak et al. realize CdTe and CdSe quantum dots with single cobalt and manganese ions and show how the quantum dot design influences single-spin relaxation time.
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Affiliation(s)
- J Kobak
- 1] Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Hoża 69, Warsaw 00-681, Poland [2]
| | - T Smoleński
- 1] Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Hoża 69, Warsaw 00-681, Poland [2]
| | - M Goryca
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Hoża 69, Warsaw 00-681, Poland
| | - M Papaj
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Hoża 69, Warsaw 00-681, Poland
| | - K Gietka
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Hoża 69, Warsaw 00-681, Poland
| | - A Bogucki
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Hoża 69, Warsaw 00-681, Poland
| | - M Koperski
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Hoża 69, Warsaw 00-681, Poland
| | - J-G Rousset
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Hoża 69, Warsaw 00-681, Poland
| | - J Suffczyński
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Hoża 69, Warsaw 00-681, Poland
| | - E Janik
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Hoża 69, Warsaw 00-681, Poland
| | - M Nawrocki
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Hoża 69, Warsaw 00-681, Poland
| | - A Golnik
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Hoża 69, Warsaw 00-681, Poland
| | - P Kossacki
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Hoża 69, Warsaw 00-681, Poland
| | - W Pacuski
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Hoża 69, Warsaw 00-681, Poland
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Tunsiri S, Thammawongsa N, Mitatha S, Yupapin PP. Molecular transport network security using multi-wavelength optical spins. ARTIFICIAL CELLS NANOMEDICINE AND BIOTECHNOLOGY 2014; 44:240-7. [DOI: 10.3109/21691401.2014.940083] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Affiliation(s)
- Michael E Flatté
- Optical Science and Technology Center and the Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242, USA
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Qu F, Moura FV, Alves FM, Gargano R. Optical tunability of magnetic polaron stability in single-Mn doped bulk GaAs and GaAs/AlGaAs quantum dots. Chem Phys Lett 2013. [DOI: 10.1016/j.cplett.2013.01.042] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Cronenberger S, Vladimirova M, Andreev SV, Lifshits MB, Scalbert D. Optical pump-probe detection of manganese hyperfine beats in (Cd,Mn)Te crystals. PHYSICAL REVIEW LETTERS 2013; 110:077403. [PMID: 25166407 DOI: 10.1103/physrevlett.110.077403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Indexed: 06/03/2023]
Abstract
Optical pump-probe experiments reveal spin beats of manganese ions in (Cd,Mn)Te, due to hyperfine and crystal fields. At "magic" orientations of the magnetic field, the effect of local crystal field is strongly suppressed. In this case, the spin precession of Mn(2+) embedded in the lattice approaches the precession expected for the free ion. Following optical excitation, regular spin pulses show up, revealing the one-to-one correspondence between precession frequency and Mn(2+) nuclear spin state. The period of the spin pulses accurately determines the hyperfine constant |A|=705 neV. The manganese spin coherence time up to T(2)(Mn)≃15 ns is measured for a manganese concentration x=0.0011.
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Affiliation(s)
- S Cronenberger
- Laboratoire Charles Coulomb UMR 5221 CNRS/UM2, Université Montpellier 2, Place Eugene Bataillon, 34095 Montpellier Cedex 05, France
| | - M Vladimirova
- Laboratoire Charles Coulomb UMR 5221 CNRS/UM2, Université Montpellier 2, Place Eugene Bataillon, 34095 Montpellier Cedex 05, France
| | - S V Andreev
- Laboratoire Charles Coulomb UMR 5221 CNRS/UM2, Université Montpellier 2, Place Eugene Bataillon, 34095 Montpellier Cedex 05, France
| | - M B Lifshits
- Laboratoire Charles Coulomb UMR 5221 CNRS/UM2, Université Montpellier 2, Place Eugene Bataillon, 34095 Montpellier Cedex 05, France and Ioffe Physical-Technical Institute of the RAS, 26, Politechnicheskaya, 194021 Saint-Petersburg, Russia
| | - D Scalbert
- Laboratoire Charles Coulomb UMR 5221 CNRS/UM2, Université Montpellier 2, Place Eugene Bataillon, 34095 Montpellier Cedex 05, France
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MITATHA S, GLOMEGLOM S, TEEKA C, ALI J, YUPAPIN PP. SOLITON SPIN AND WAVE-PARTICLE DUALITY. ACTA ACUST UNITED AC 2011. [DOI: 10.1142/s1793528811000202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Baudin E, Benjamin E, Lemaître A, Krebs O. Optical pumping and a nondestructive readout of a single magnetic impurity spin in an InAs/GaAs quantum dot. PHYSICAL REVIEW LETTERS 2011; 107:197402. [PMID: 22181643 DOI: 10.1103/physrevlett.107.197402] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Indexed: 05/31/2023]
Abstract
We report on the resonant optical pumping of the | ± 1⟩ spin states of a single Mn dopant in an InAs/GaAs quantum dot which is embedded in a charge tunable device. The experiment relies on a W scheme of transitions reached when a suitable longitudinal magnetic field is applied. The optical pumping is achieved via the resonant excitation of the central Λ system at the neutral exciton X(0) energy. For a specific gate voltage, the redshifted photoluminescence of the charged exciton X- is observed, which allows a nondestructive readout of the spin polarization. An arbitrary spin preparation in the | + 1⟩ or |-1⟩ state characterized by a polarization near or above 50% is evidenced.
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Affiliation(s)
- E Baudin
- CNRS-Laboratoire de Photonique et de Nanostructures, Route de Nozay, 91460 Marcoussis, France
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Abstract
The sensitive dependence of a semiconductor's electronic, optical and magnetic properties on dopants has provided an extensive range of tunable phenomena to explore and apply to devices. Recently it has become possible to move past the tunable properties of an ensemble of dopants to identify the effects of a solitary dopant on commercial device performance as well as locally on the fundamental properties of a semiconductor. New applications that require the discrete character of a single dopant, such as single-spin devices in the area of quantum information or single-dopant transistors, demand a further focus on the properties of a specific dopant. This article describes the huge advances in the past decade towards observing, controllably creating and manipulating single dopants, as well as their application in novel devices which allow opening the new field of solotronics (solitary dopant optoelectronics).
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Affiliation(s)
- Paul M Koenraad
- COBRA Inter-University Research Institute, Department of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands.
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Paraïso TK, Wouters M, Léger Y, Morier-Genoud F, Deveaud-Plédran B. Multistability of a coherent spin ensemble in a semiconductor microcavity. NATURE MATERIALS 2010; 9:655-660. [PMID: 20601942 DOI: 10.1038/nmat2787] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Accepted: 05/22/2010] [Indexed: 05/29/2023]
Abstract
Coherent manipulation of spin ensembles is a key issue in the development of spintronics. In particular, multivalued spin switching may lead to new schemes of logic gating and memories. This phenomenon has been studied with atom vapours 30 years ago, but is still awaited in the solid state. Here, we demonstrate spin multistability with microcavity polaritons in a trap. Owing to the spinor nature of these light-matter quasiparticles and to the anisotropy of their interactions, we can optically control the spin state of a single confined level by tuning the excitation power, frequency and polarization. First, we realize high-efficiency power-dependent polarization switching. Then, at constant excitation power, we evidence polarization hysteresis and determine the conditions for realizing multivalued spin switching. Finally, we demonstrate an unexpected regime, where our system behaves as a high-contrast spin trigger. These results open new pathways to the development of advanced spintronics devices and to the realization of multivalued logic circuits.
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Affiliation(s)
- T K Paraïso
- Laboratory of Quantum Optoelectronics, EPFL, CH-1015, Lausanne, Switzerland.
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Moriyasu T, Nomoto D, Koyama Y, Fukuda Y, Kohmoto T. Spin manipulation using the light-shift effect in rubidium atoms. PHYSICAL REVIEW LETTERS 2009; 103:213602. [PMID: 20366036 DOI: 10.1103/physrevlett.103.213602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2009] [Indexed: 05/29/2023]
Abstract
Optical manipulation of spin coherence in rubidium atoms is studied. The effect of off-resonant and circularly polarized light on optically induced magnetization is investigated. The change in precession frequency caused by the light-shift effect is verified. Absorption-free phase control of spin precession and pure spin rotation about an arbitrary axis are demonstrated. A theory of precession frequency shift that includes the effect of absorption is considered by using the density matrix and the experimental results are in agreement with the predictions of the theory. Thus, we show that it is possible to carry out off-resonant control of spin coherence and all-optical manipulation of spins.
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Affiliation(s)
- T Moriyasu
- Graduate School of Science, Kobe University, Kobe 657-8501, Japan
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Beaulac R, Schneider L, Archer PI, Bacher G, Gamelin DR. Light-induced spontaneous magnetization in doped colloidal quantum dots. Science 2009; 325:973-6. [PMID: 19696345 DOI: 10.1126/science.1174419] [Citation(s) in RCA: 135] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
An attractive approach to controlling spin effects in semiconductor nanostructures for applications in electronics is the use of light to generate, manipulate, or read out spins. Here, we demonstrate spontaneous photoinduced polarization of manganese(II) spins in doped colloidal cadmium selenide quantum dots. Photoexcitation generates large dopant-carrier exchange fields, enhanced by strong spatial confinement, that lead to giant Zeeman splittings of the semiconductor band structure in the absence of applied magnetic fields. These internal exchange fields allow spontaneous magnetic saturation of the manganese(II) spins to be achieved at zero external magnetic field up to approximately 50 kelvin. Photomagnetic effects are observed all the way up to room temperature.
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Affiliation(s)
- Rémi Beaulac
- Department of Chemistry, University of Washington, Seattle, WA 98195-1700, USA
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Le Gall C, Besombes L, Boukari H, Kolodka R, Cibert J, Mariette H. Optical spin orientation of a single manganese atom in a semiconductor quantum dot using quasiresonant photoexcitation. PHYSICAL REVIEW LETTERS 2009; 102:127402. [PMID: 19392322 DOI: 10.1103/physrevlett.102.127402] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2008] [Indexed: 05/27/2023]
Abstract
An optical spin orientation is achieved for a Mn atom localized in a semiconductor quantum dot using quasiresonant excitation at zero magnetic field. Optically created spin-polarized carriers generate an energy splitting of the Mn spin and enable magnetic moment orientation controlled by the photon helicity and energy. The dynamics and the magnetic field dependence of the optical pumping mechanism show that the spin lifetime of an isolated Mn atom at zero magnetic field is controlled by a magnetic anisotropy induced by the built-in strain in the quantum dots.
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Affiliation(s)
- C Le Gall
- Université Joseph Fourier, 38042 Grenoble, France
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