scholarly journals Magnetothermoelectric Effects of 2D Electron Gas in Quantum Well with Parabolic Confinement Potential in-plane Magnetic Field

2010 ◽  
Vol 245 ◽  
pp. 012015 ◽  
Author(s):  
F M Hashimzade ◽  
M M Babayev ◽  
B H Mehdiyev ◽  
Kh A Hasanov
Keyword(s):  
Magnetic Field ◽  
Quantum Well ◽  
Electron Gas ◽  
2D Electron Gas ◽  
Confinement Potential ◽  
Parabolic Confinement ◽  
Parabolic Confinement Potential

scholarly journals TRANSPORT PROPERTIES OF 2D ELECTRON GAS IN AN n-InGaAs/GaAs DQW IN A VICINITY OF LOW MAGNETIC-FIELD-INDUCED HALL INSULATOR–QUANTUM HALL LIQUID TRANSITION

2007 ◽  
Vol 06 (03n04) ◽  
pp. 173-177
Author(s):  
YU. G. ARAPOV ◽  
S. V. GUDINA ◽  
G. I. HARUS ◽  
V. N. NEVEROV ◽  
N. G. SHELUSHININA ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electron Gas ◽  
Quantum Hall ◽  
Zero Magnetic Field ◽  
Double Quantum ◽  
Ballistic Regime ◽  
2D Electron Gas ◽  
Double Quantum Well ◽  
Liquid Transition ◽  
Low Magnetic Field

The resistivity (ρ) of low mobility dilute 2D electron gas in an n- InGaAs / GaAs double quantum well (DQW) exhibits the monotonic "insulating-like" temperature dependence (dρ/dT < 0) at T = 1.8–70 K in zero magnetic field. This temperature interval corresponds to a ballistic regime (kBTτ/ħ > 0.1–3.5) for our samples, and the electron density is on an "insulating" side of the so-called B = 0 2D metal–insulator transition. We show that the observed features of localization and Landau quantization in a vicinity of the low magnetic-field-induced insulator–quantum Hall liquid transition is due to the σxy(T) anomalous T-dependence.

Coherent nonlinear low-frequency Landau–Zener tunneling induced by magnetic control of a spin qubit in a quantum wire

2018 ◽  
Vol 16 (06) ◽  
pp. 1850049
Author(s):  
S. E. Mkam Tchouobiap ◽  
J. E. Danga ◽  
R. M. Keumo Tsiaze ◽  
L. C. Fai
Keyword(s):  
Quantum Wire ◽  
Modulation Frequency ◽  
Strong Dependence ◽  
Rabi Oscillation ◽  
Low Frequency ◽  
Dynamical Evolution ◽  
Quantum Bit ◽  
Confinement Potential ◽  
Parabolic Confinement ◽  
Parabolic Confinement Potential

This paper presents nonlinear Landau–Zener (LZ) tunneling of an electron spin in an accelerating optical parabolic potential, manifested in a heterostructure quantum wire subjected to a periodic magnetic field comprising a spike and a homogeneous part. In this context, driving the two states of a pure nonlinear two-level quantum bit (qubit) system through an avoided level crossing can result in nontrivial dynamics, especially with and without considering a parabolic confinement potential characterized by a curvature confinement potential. We report two striking nonadiabatic and adiabatic scenarios in low modulation frequency limit which appear when such strength modulation occurs. Firstly, the changes of the amplitude of the driving field without considering a parabolic confinement potential act as a perturbation which mixes the spin states. Here, the dynamical evolution of the tunneling probabilities of the nonadiabatic populations under investigation is analyzed. Secondly, for strong fields and strong dependence of a parabolic confinement potential, the two diabatic states do not cross but present anti-crossing phenomenon as the time tends to infinity, describing an adiabatic transition. However, if the field strength in a wire is weak enough, the level separation of a qubit state switches abruptly around the crossing point, and LZ tunneling applies to the whole dynamical range, from adiabatic to fully nonadiabatic crossing. Locally, the tunneling process can be seen as a two-level system (TLS) undergoing a Rabi oscillation. These results open new prospects for the use of quantum interferences in spin–based devices.

scholarly journals Investigation of Light Absorption in a ZnS Quantum Dot

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Hojjatollah K. Salehani ◽  
Maedeh Zakeri
Keyword(s):  
Magnetic Field ◽  
Optical Absorption ◽  
Quantum Dot ◽  
Excited States ◽  
Light Absorption ◽  
Blue Shift ◽  
Optical Absorption Coefficient ◽  
Parabolic Confinement ◽  
Parabolic Confinement Potential ◽  
The Magnetic Field

The light absorption of a ZnS quantum dot with a parabolic confinement potential is studied in this paper in the presence of magnetic field perpendicular to dot plane. The Schrodinger equation of a single electron is solved numerically, and energy spectra and wave functions are obtained. Then, the optical absorption coefficients in transition from ground state to different excited states are calculated. The effects the magnetic field and quantum dot width on the optical absorption are investigated. It is found that the optical absorption coefficient has a blue shift by increasing of magnetic field or confinement strength of quantum dot.

Ring interferometer on the basis of 2D electron gas in a double quantum well

JETP Letters ◽  
2003 ◽  
Vol 78 (9) ◽  
pp. 560-563
Author(s):  
A. A. Bykov ◽  
D. V. Nomokonov ◽  
A. K. Bakarov ◽  
A. I. Toropov ◽  
O. Estibals ◽  
...  
Keyword(s):  
Quantum Well ◽  
Electron Gas ◽  
Double Quantum ◽  
2D Electron Gas ◽  
Ring Interferometer ◽  
Double Quantum Well

Exchange Enhancement of g-Factor in Narrow-Gap InAs/AlSb Quantum Well Heterostructures

2012 ◽  
Vol 190 ◽  
pp. 554-557 ◽  
Author(s):  
S.S. Krishtopenko ◽  
V.I. Gavrilenko ◽  
M. Goiran
Keyword(s):  
Quantum Well ◽  
Landau Level ◽  
Electron Gas ◽  
Semiconductor Heterostructures ◽  
Electron Interaction ◽  
Narrow Gap ◽  
G Factor ◽  
2D Electron Gas ◽  
Level Width ◽  
Exchange Enhancement

We report on the study of exchange enhancement of g-factor in 2D electron gas in n-type narrow-gap semiconductor heterostructures that feature a strong nonparabolicity of electric subbands. We demonstrate that exchange g-factor enhancement not only shows maxima at odd values of Landau level filling factors but, due to subband nonparabolicity, persists at even filling factor values as well. The magnitude of the exchange enhancement, the amplitude and shape of the g-factor oscillations are governed by both the screening of electron-electron interaction and the Landau level width. The enhanced g-factor values calculated for 2D electron gas in InAs/AlSb quantum well heterostructures are compared with previous experimental magnetotransport data.

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