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Pusep YA, Teodoro MD, Laurindo V, Cardozo de Oliveira ER, Gusev GM, Bakarov AK. Diffusion of Photoexcited Holes in a Viscous Electron Fluid. Phys Rev Lett 2022; 128:136801. [PMID: 35426705 DOI: 10.1103/physrevlett.128.136801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 02/03/2022] [Accepted: 02/24/2022] [Indexed: 06/14/2023]
Abstract
The diffusion of photogenerated holes is studied in a high-mobility mesoscopic GaAs channel where electrons exhibit hydrodynamic properties. It is shown that the injection of holes into such an electron system leads to the formation of a hydrodynamic three-component mixture consisting of electrons and photogenerated heavy and light holes. The obtained results are analyzed within the framework of ambipolar diffusion, which reveals characteristics of a viscous flow. Both hole types exhibit similar hydrodynamic characteristics. In such a way the diffusion lengths, ambipolar diffusion coefficient, and the effective viscosity of the electron-hole system are determined.
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Affiliation(s)
- Yu A Pusep
- São Carlos Institute of Physics, University of São Paulo, P.O. Box 369, 13560-970 São Carlos, São Paulo, Brazil
| | - M D Teodoro
- Departamento de Física, Universidade Federal de São Carlos, 13565-905 São Carlos, São Paulo, Brazil
| | - V Laurindo
- Departamento de Física, Universidade Federal de São Carlos, 13565-905 São Carlos, São Paulo, Brazil
| | - E R Cardozo de Oliveira
- Departamento de Física, Universidade Federal de São Carlos, 13565-905 São Carlos, São Paulo, Brazil
| | - G M Gusev
- Institute of Physics, University of São Paulo, 135960-170 São Paulo, São Paulo, Brazil
| | - A K Bakarov
- Institute of Semiconductor Physics, 630090 Novosibirsk, Russia
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Lyamkina AA, Schraml K, Regler A, Schalk M, Bakarov AK, Toropov AI, Moshchenko SP, Kaniber M. Monolithically integrated single quantum dots coupled to bowtie nanoantennas. Opt Express 2016; 24:28936-28944. [PMID: 27958558 DOI: 10.1364/oe.24.028936] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Deterministically integrating semiconductor quantum emitters with plasmonic nano-devices paves the way towards chip-scale integrable, true nanoscale quantum photonic technologies. For this purpose, stable and bright semiconductor emitters are needed, which moreover allow for CMOS-compatibility and optical activity in the telecommunication band. Here, we demonstrate strongly enhanced light-matter coupling of single near-surface (< 10 nm) InAs quantum dots monolithically integrated into electromagnetic hot-spots of sub-wavelength sized metal nanoantennas. The antenna strongly enhances the emission intensity of single quantum dots by up to ~ 16×, an effect accompanied by an up to 3.4× Purcell-enhanced spontaneous emission rate. Moreover, the emission is strongly polarised along the antenna axis with degrees of linear polarisation up to ~ 85 %. The results unambiguously demonstrate a pronounced coupling of individual quantum dots to state-of-the-art nanoantennas. Our work provides new perspectives for the realisation of quantum plasmonic sensors, step-changing photovoltaic devices, bright and ultrafast quantum light sources and efficient nano-lasers.
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Shevyrin AA, Pogosov AG, Bakarov AK, Shklyaev AA. Piezoelectric Electromechanical Coupling in Nanomechanical Resonators with a Two-Dimensional Electron Gas. Phys Rev Lett 2016; 117:017702. [PMID: 27419592 DOI: 10.1103/physrevlett.117.017702] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Indexed: 06/06/2023]
Abstract
The electrical response of a two-dimensional electron gas to vibrations of a nanomechanical cantilever containing it is studied. Vibrations of perpendicularly oriented cantilevers are experimentally shown to oppositely change the conductivity near their bases. This indicates the piezoelectric nature of electromechanical coupling. A physical model is developed, which quantitatively explains the experiment. It shows that the main origin of the conductivity change is a rapid change in the mechanical stress on the boundary between suspended and nonsuspended areas, rather than the stress itself.
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Affiliation(s)
- A A Shevyrin
- Rzhanov Institute of Semiconductor Physics 13, Lavrentyev Avenue, Novosibirsk 630090, Russia, and Novosibirsk State University 2, Pirogov Street, Novosibirsk 630090, Russia
| | - A G Pogosov
- Rzhanov Institute of Semiconductor Physics 13, Lavrentyev Avenue, Novosibirsk 630090, Russia, and Novosibirsk State University 2, Pirogov Street, Novosibirsk 630090, Russia
| | - A K Bakarov
- Rzhanov Institute of Semiconductor Physics 13, Lavrentyev Avenue, Novosibirsk 630090, Russia, and Novosibirsk State University 2, Pirogov Street, Novosibirsk 630090, Russia
| | - A A Shklyaev
- Rzhanov Institute of Semiconductor Physics 13, Lavrentyev Avenue, Novosibirsk 630090, Russia, and Novosibirsk State University 2, Pirogov Street, Novosibirsk 630090, Russia
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dos Santos LF, Castelano LK, Padilha JX, Pusep Y, Marques GE, Smirnov D, Bakarov AK, Toropov AI, Lopez-Richard V. Excitonic spin-splitting in quantum wells with a tilted magnetic field. J Phys Condens Matter 2016; 28:055503. [PMID: 26766872 DOI: 10.1088/0953-8984/28/5/055503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
This work aims to investigate the effects of magnetic field strength and direction on the electronic properties and optical response of GaAs/AlGaAs-based heterostructures. An investigation of the excitonic spin-splitting of a disordered multiple quantum well embedded in a wide parabolic quantum well is presented. The results for polarization-resolved photoluminescence show that the magnetic field dependencies of the excitonic spin-splitting and photoluminescence linewidth are crucially sensitive to magnetic field orientation. Our experimental results are in good agreement with the calculated Zeeman splitting obtained by the Luttinger model, which predicts a hybridization of the spin character of states in the valence band under tilted magnetic fields.
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Levin AD, Momtaz ZS, Gusev GM, Raichev OE, Bakarov AK. Microwave-Induced Magneto-Oscillations and Signatures of Zero-Resistance States in Phonon-Drag Voltage in Two-Dimensional Electron Systems. Phys Rev Lett 2015; 115:206801. [PMID: 26613460 DOI: 10.1103/physrevlett.115.206801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Indexed: 06/05/2023]
Abstract
We observe the phonon-drag voltage oscillations correlating with the resistance oscillations under microwave irradiation in a two-dimensional electron gas in perpendicular magnetic field. This phenomenon is explained by the influence of dissipative resistivity modified by microwaves on the phonon-drag voltage perpendicular to the phonon flux. When the lowest-order resistance minima evolve into zero-resistance states, the phonon-drag voltage demonstrates sharp features suggesting that current domains associated with these states can exist in the absence of external dc driving.
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Affiliation(s)
- A D Levin
- Instituto de Física da Universidade de São Paulo, 135960-170 São Paulo, Brazil
| | - Z S Momtaz
- Instituto de Física da Universidade de São Paulo, 135960-170 São Paulo, Brazil
| | - G M Gusev
- Instituto de Física da Universidade de São Paulo, 135960-170 São Paulo, Brazil
| | - O E Raichev
- Institute of Semiconductor Physics, NAS of Ukraine, Prospekt Nauki 41, 03028 Kyiv, Ukraine
| | - A K Bakarov
- Institute of Semiconductor Physics, Novosibirsk 630090, Russia
- Novosibirsk State University, Novosibirsk 630090, Russia
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Pusep YA, Fernandes dos Santos L, Gusev GM, Smirnov D, Bakarov AK. Circularly polarized photoluminescence as a probe of density of states in GaAs/AlGaAs quantum Hall bilayers. Phys Rev Lett 2012; 109:046802. [PMID: 23006102 DOI: 10.1103/physrevlett.109.046802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Indexed: 06/01/2023]
Abstract
Polarized magnetophotoluminescence is employed to study the energies and occupancies of four lowest Landau levels in a couple quantum Hall GaAs/AlGaAs double quantum well. As a result, a magnetic field-induced redistribution of charge over the Landau levels manifesting to the continuous formation of the charge density wave and direct evidence for the symmetric-antisymmetric gap shrinkage at ν=3 are found. The observed interlayer charge exchange causes depolarization of the ferromagnetic ground state.
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Affiliation(s)
- Yu A Pusep
- Instituto de Fisica de São Carlos, Universidade de São Paulo, 13560-970 Sao Carlos, São Paulo, Brazil
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Wiedmann S, Gusev GM, Raichev OE, Bakarov AK, Portal JC. Microwave zero-resistance states in a bilayer electron system. Phys Rev Lett 2010; 105:026804. [PMID: 20867726 DOI: 10.1103/physrevlett.105.026804] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Indexed: 05/29/2023]
Abstract
Magnetotransport measurements on a high-mobility electron bilayer system formed in a wide GaAs quantum well reveal vanishing dissipative resistance under continuous microwave irradiation. Profound zero-resistance states (ZRS) appear even in the presence of additional intersubband scattering of electrons. We study the dependence of photoresistance on frequency, microwave power, and temperature. Experimental results are compared with a theory demonstrating that the conditions for absolute negative resistivity correlate with the appearance of ZRS.
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Affiliation(s)
- S Wiedmann
- LNCMI-CNRS, UPR 3228, BP 166, 38042 Grenoble Cedex 9, France
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Gusev GM, Bakarov AK, Lamas TE, Portal JC. Reentrant quantum Hall effect and anisotropic transport in a bilayer system at high filling factors. Phys Rev Lett 2007; 99:126804. [PMID: 17930539 DOI: 10.1103/physrevlett.99.126804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2007] [Indexed: 05/25/2023]
Abstract
We report on the measurements of the quantum Hall effect states in double quantum well structures at the filling factors nu=4N+1 and nu=4N+3, where N is the Landau index number, in the presence of the in-plane magnetic field. The quantum Hall states at these filling factors vanish and reappear several times and exhibit anisotropy. Repeated reentrance of the transport gap occurs due to the periodic vanishing of the tunneling amplitude in the presence of the in-plane field. Anisotropy demonstrates the existence of the stripes in the ground states.
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Affiliation(s)
- G M Gusev
- Instituto de Física da Universidade de São Paulo, CP 66318 CEP 05315-970, São Paulo, SP, Brazil
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Bykov AA, Zhang JQ, Vitkalov S, Kalagin AK, Bakarov AK. Zero-differential resistance state of two-dimensional electron systems in strong magnetic fields. Phys Rev Lett 2007; 99:116801. [PMID: 17930458 DOI: 10.1103/physrevlett.99.116801] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2007] [Indexed: 05/25/2023]
Abstract
We report the observation of a zero-differential resistance state (ZDRS) in response to a direct current above a threshold value I>I th applied to a two-dimensional system of electrons at low temperatures in a strong magnetic field. Entry into the ZDRS, which is not observable above several Kelvins, is accompanied by a sharp dip in the differential resistance. Additional analysis reveals an instability of the electrons for I>I th and an inhomogeneous, nonstationary pattern of the electric current. We suggest that the dominant mechanism leading to the new electron state is a redistribution of electrons in energy space induced by the direct current.
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Affiliation(s)
- A A Bykov
- Physics Department, City College of the City University of New York, New York 10031, USA
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Scholz M, Büettner S, Benson O, Toropov AI, Bakarov AK, Kalagin AK, Lochmann A, Stock E, Schulz O, Hopfer F, Haisler VA, Bimberg D. Non-classical light emission from a single electrically driven quantum dot. Opt Express 2007; 15:9107-9112. [PMID: 19547250 DOI: 10.1364/oe.15.009107] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Easy to handle light sources with non-classical emission features are strongly demanded in the growing field of quantum communication. We report on single-photon emission from an electrically pumped quantum dot with unmatched spectral purity, making spatial or spectral filtering dispensable.
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