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Park S, Kim M, Kim I, Taylor RA, Song J, Kyhm K. Elliptical Polarization of Localized States in an Anisotropic Single GaAs Quantum Ring. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 13:184. [PMID: 36616094 PMCID: PMC9823924 DOI: 10.3390/nano13010184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 12/23/2022] [Accepted: 12/29/2022] [Indexed: 06/17/2023]
Abstract
Localized states in an anisotropic single GaAs quantum ring were investigated in terms of polarization dependence of micro-photoluminescence spectrum at 5K. Given four Stokes parameters measured with a pair of linear polarizers and waveplates, the elliptical polarization states of two different vertical confinement states (k=1 and k=2) were compared with phase, rotation, and ellipticity angles. While the polarized emission intensity of the k=2 states becomes enhanced along [1,1,0] compared to that along [1,1¯,0], the polarization asymmetry of the k=1 states shows the opposite result. We conclude the polarization state is determined by the shape of the lateral wavefunctions. In the k=2 state, crescent-like wavefunctions are strongly localized, but the k=1 state consists of two crescent-like wavefunctions, which are connected weakly through quantum tunneling.
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Affiliation(s)
- Seongho Park
- Department of Opto/Cogno-Mechatronics Engineering, Research Center for Dielectric Advanced Matter Physic (RCDAMP), Pusan National University, Busan 46241, Republic of Korea
| | - Minju Kim
- Smart Gym-Based Translational Research Center for Active Senior’s Healthcare, Pukyong National University, Busan 48516, Republic of Korea
| | - Inhong Kim
- Department of Opto/Cogno-Mechatronics Engineering, Research Center for Dielectric Advanced Matter Physic (RCDAMP), Pusan National University, Busan 46241, Republic of Korea
| | | | - Jindong Song
- Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
| | - Kwangseuk Kyhm
- Department of Opto/Cogno-Mechatronics Engineering, Research Center for Dielectric Advanced Matter Physic (RCDAMP), Pusan National University, Busan 46241, Republic of Korea
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Corfdir P, Marquardt O, Lewis RB, Sinito C, Ramsteiner M, Trampert A, Jahn U, Geelhaar L, Brandt O, Fomin VM. Excitonic Aharonov-Bohm Oscillations in Core-Shell Nanowires. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1805645. [PMID: 30461088 DOI: 10.1002/adma.201805645] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 10/15/2018] [Indexed: 06/09/2023]
Abstract
Phase coherence in nanostructures is at the heart of a wide range of quantum effects such as Josephson oscillations between exciton-polariton condensates in microcavities, conductance quantization in 1D ballistic transport, or the optical (excitonic) Aharonov-Bohm effect in semiconductor quantum rings. These effects only occur in structures of the highest perfection. The 2D semiconductor heterostructures required for the observation of Aharonov-Bohm oscillations have proved to be particularly demanding, since interface roughness or alloy fluctuations cause a loss of the spatial phase coherence of excitons, and ultimately induce exciton localization. Experimental work in this field has so far relied on either self-assembled ring structures with very limited control of shape and dimension or on lithographically defined nanorings that suffer from the detrimental effects of free surfaces. Here, it is demonstrated that nanowires are an ideal platform for studies of the Aharonov-Bohm effect of neutral and charged excitons, as they facilitate the controlled fabrication of nearly ideal quantum rings by combining all-binary radial heterostructures with axial crystal-phase quantum structures. Thanks to the atomically flat interfaces and the absence of alloy disorder, excitonic phase coherence is preserved even in rings with circumferences as large as 200 nm.
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Affiliation(s)
- Pierre Corfdir
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e. V., Hausvogteiplatz 5-7, 10117, Berlin, Germany
| | - Oliver Marquardt
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e. V., Hausvogteiplatz 5-7, 10117, Berlin, Germany
- Weierstraß-Institut für Angewandte Analysis und Stochastik, Leibniz-Institut im Forschungsverbund Berlin e. V., Mohrenstraße 39, 10117, Berlin, Germany
| | - Ryan B Lewis
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e. V., Hausvogteiplatz 5-7, 10117, Berlin, Germany
| | - Chiara Sinito
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e. V., Hausvogteiplatz 5-7, 10117, Berlin, Germany
| | - Manfred Ramsteiner
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e. V., Hausvogteiplatz 5-7, 10117, Berlin, Germany
| | - Achim Trampert
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e. V., Hausvogteiplatz 5-7, 10117, Berlin, Germany
| | - Uwe Jahn
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e. V., Hausvogteiplatz 5-7, 10117, Berlin, Germany
| | - Lutz Geelhaar
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e. V., Hausvogteiplatz 5-7, 10117, Berlin, Germany
| | - Oliver Brandt
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e. V., Hausvogteiplatz 5-7, 10117, Berlin, Germany
| | - Vladimir M Fomin
- Institute for Integrative Nanosciences, Leibniz IFW Dresden, Helmholtzstraße 20, 01069, Dresden, Germany
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Kim H, Park S, Okuyama R, Kyhm K, Eto M, Taylor RA, Nogues G, Dang LS, Potemski M, Je K, Kim J, Kyhm J, Song J. Light Controlled Optical Aharonov-Bohm Oscillations in a Single Quantum Ring. NANO LETTERS 2018; 18:6188-6194. [PMID: 30223652 DOI: 10.1021/acs.nanolett.8b02131] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We found that optical Aharonov-Bohm oscillations in a single GaAs/GaAlAs quantum ring can be controlled by excitation intensity. With a weak excitation intensity of 1.2 kW cm-2, the optical Aharonov-Bohm oscillation period of biexcitons was observed to be half that of excitons in accordance with the period expected for a two-exciton Wigner molecule. When the excitation intensity is increased by an order of magnitude (12 kW cm-2), a gradual deviation of the Wigner molecule condition occurs with decreased oscillation periods and diamagnetic coefficients for both excitons and biexcitons along with a spectral shift. These results suggest that the effective orbit radii and rim widths of electrons and holes in a single quantum ring can be modified by light intensity via photoexcited carriers, which are possibly trapped at interface defects resulting in a local electric field.
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Affiliation(s)
- Heedae Kim
- School of Physics , Northeast Normal University , Changchun 130024 , China
- Clarendon Laboratory, Department of Physics , University of Oxford , Oxford OX1 3PU , U.K
| | - Seongho Park
- Department of Opto-mechatronics, Cogno-mechatronics, Physics Education , Pusan Nat'l University , Busan 609-735 , South Korea
| | - Rin Okuyama
- Faculty of Science and Technology , Keio University , Yokohama 223-8522 , Japan
| | - Kwangseuk Kyhm
- Department of Opto-mechatronics, Cogno-mechatronics, Physics Education , Pusan Nat'l University , Busan 609-735 , South Korea
| | - Mikio Eto
- Faculty of Science and Technology , Keio University , Yokohama 223-8522 , Japan
| | - Robert A Taylor
- Clarendon Laboratory, Department of Physics , University of Oxford , Oxford OX1 3PU , U.K
| | - Gilles Nogues
- Department of NANOscience , Institut Néel, CNRS , rue des Martyrs , 38054 Grenoble , France
| | - Le Si Dang
- Department of NANOscience , Institut Néel, CNRS , rue des Martyrs , 38054 Grenoble , France
| | - Marek Potemski
- Laboratoire National des Champs Magnetiques Intenses , CNRS-UJF-UPS-INSA , F-38042 , Grenoble , France
| | - Koochul Je
- Institute of Physics, Faculty of Natural Science and Mathematics , Sts Cyril and Methodius University , 1000 Skopje , Macedonia
| | - Jongsu Kim
- Department of Physics , Yeungnam University , Gyeonsan 712-749 , South Korea
| | - Jihoon Kyhm
- Center for Optoelectronic Convergence Systems , KIST , Seoul 136-791 , South Korea
| | - Jindong Song
- Center for Optoelectronic Convergence Systems , KIST , Seoul 136-791 , South Korea
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Molecular spectrum of laterally coupled quantum rings under intense terahertz radiation. Sci Rep 2017; 7:10485. [PMID: 28874715 PMCID: PMC5585341 DOI: 10.1038/s41598-017-10877-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 08/11/2017] [Indexed: 11/09/2022] Open
Abstract
We study the influence of intense THz laser radiation and electric field on molecular states of laterally coupled quantum rings. Laser radiation shows the capability to dissociate quantum ring molecule and add 2-fold degeneracy to the molecular states at the fixed value of the overlapping size between rings. It is shown that coupled to decoupled molecular states phase transition points form almost a straight line with a slope equal to two. In addition, the electric field direction dependent energy spectrum shows unexpected oscillations, demonstrating strong coupling between molecular states. Besides, intraband absorption is considered, showing both blue and redshifts in its spectrum. The obtained results can be useful for the controlling of degeneracy of the discrete energy spectrum of nanoscale structures and in the tunneling effects therein.
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