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Related papers: Multi-subband effect in spin dephasing in semicond…

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We set up a set of many-body kinetic Bloch equations with spacial inhomogeneity. We reexamine the widely adopted quasi-independent electron model (QIEM) and show the inadequacy of this model in studying the spin transport. We further point…

Condensed Matter · Physics 2007-05-23 M. Q. Weng , M. W. Wu

Utilizing time-resolved Kerr rotation techniques, we have investigated the spin dynamics of a high mobility, low density two dimensional electron gas in a GaAs/Al0:35Ga0:65As heterostructure in dependence on temperature from 1.5 K to 30 K.…

Other Condensed Matter · Physics 2009-11-13 X. Z. Ruan , H. H. Luo , Yang Ji , Z. Y. Xu , V. Umansky

The D'yakonov-Perel' mechanism, intimately related to the spin splitting of the electronic states, usually dominates the spin relaxation in zinc blende semiconductor quantum structures. Previously it has been formulated for the two limiting…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 J. Kainz , U. Rossler , R. Winkler

Under an in-plane magnetic field, the density of states of quasi two-dimensional carriers deviates from the occasionally stereotypic step-like form both quantitatively and qualitatively. For the first time, we study how this affects the…

Materials Science · Physics 2008-02-04 Constantinos Simserides

We report theoretical and experimental studies of ambipolar spin diffusion in a semiconductor. A circularly polarized laser pulse is used to excite spin-polarized carriers in a GaAs multiple quantum well sample at 80 K. Diffusion of…

Mesoscale and Nanoscale Physics · Physics 2009-03-31 Hui Zhao , Matt Mower , G. Vignale

We present a detailed experimental and theoretical analysis of the spin dynamics of two-dimensional electron gases (2DEGs) in a series of n-doped GaAs/AlGaAs quantum wells. Picosecond-resolution polarized pump-probe reflection techniques…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 W. J. H. Leyland , G. H. John , R. T. Harley , M. M. Glazov , E. L. Ivchenko , D. A. Ritchie , A. J. Shields , M. Henini

We perform a theoretical investigation on the time evolution of spin pulses in an $n$-type GaAs (001) quantum well with and without external electric field at high temperatures by constructing and numerically solving the kinetic spin Bloch…

Materials Science · Physics 2007-05-23 L. Jiang , M. Q. Weng , M. W. Wu , J. L. Cheng

This study explores the relationship between spin diffusion, spin lifetime, electron density and lateral spatial confinement in two-dimensional electron gases hosted in GaAs quantum wells. Using time-resolved magneto-optical Kerr effect…

Mesoscale and Nanoscale Physics · Physics 2025-01-15 B. W. Grobecker , A. V. Poshakinskiy , S. Anghel , T. Mano , G. Yusa , M. Betz

We have studied the effect of nonequilibrium longitudinal optical phonons on hot-electron spin relaxation in $n$-type GaAs quantum wells. The longitudinal optical phonons, due to the finite relaxation rate, are driven to nonequilibrium…

Materials Science · Physics 2010-12-13 P. Zhang , M. W. Wu

Due to the competition between spatial and magnetic confinement, the density of states of a quasi two-dimensional system deviates from the ideal step-like form both quantitatively and qualitatively. We study how this affects the…

Materials Science · Physics 2009-11-13 Constantinos Simserides , Iosif Galanakis

The low-temperature($4.2<T<12.5$ K) magnetotransport ($B<2$ T) of two-dimensional electrons occupying two subbands (with energy $E_1$ and $E_2$) is investigated in GaAs single quantum well with AlAs/GaAs superlattice barriers. Two series of…

Mesoscale and Nanoscale Physics · Physics 2009-11-26 A. V. Goran , A. A. Bykov , A. I. Toropov , S. A. Vitkalov

Using time-resolved Faraday rotation, the drift-induced spin-orbit Field of a two-dimensional electron gas in an InGaAs quantum well is measured. Including measurements of the electron mobility, the Dresselhaus and Rashba coefficients are…

Mesoscale and Nanoscale Physics · Physics 2009-01-06 M. Studer , S. Schön , K. Ensslin , G. Salis

We study the optically induced spin polarization, spin dephasing and diffusion in several high-mobility two-dimensional electron systems, which are embedded in GaAs quantum wells grown on (110)-oriented substrates. The experimental…

Mesoscale and Nanoscale Physics · Physics 2015-06-17 R. Voelkl , M. Schwemmer , M. Griesbeck , S. A. Tarasenko , D. Schuh , W. Wegscheider , C. Schueller , T. Korn

Decoherence of a localized electron spin in a solid state material (the ``central spin'' problem) at low temperature is believed to be dominated by interactions with nuclear spins in the lattice. This decoherence is partially suppressed…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 W. M. Witzel , S. Das Sarma

This paper discusses the combined effects of optical excitation power, interface roughness, lattice temperature, and applied magnetic fields on the spin-coherence of excitonic states in GaAs/AlGaAs multiple quantum wells. For low optical…

The low-temperature magnetoresistance of parabolic quantum wells displays pronounced minima between integer filling factors. Concomitantly the Hall effect exhibits overshoots and plateau-like features next to well-defined ordinary quantum…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 C. Ellenberger , B. Simovic , R. Leturcq , T. Ihn , S. E. Ulloa , K. Ensslin , D. C. Driscoll , A. C. Gossard

We provide a microscopic theory for the Doppler velocimetry of spin propagation in the presence of spatial inhomogeneity, driving electric field and the spin orbit coupling in semiconductor quantum wells in a wide range of temperature…

Mesoscale and Nanoscale Physics · Physics 2012-11-12 M. Q. Weng , M. W. Wu

Experiments on a constant-density two-dimensional hole system in a GaAs quantum well reveal that the metallic behavior observed in the zero-magnetic-field temperature dependence of the resistivity depends on the symmetry of the confinement…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 S. J. Papadakis , E. P. De Poortere , H. C. Manoharan , M. Shayegan , R. Winkler

The longitudinal resistivity $\rho_{xx}$ of two-dimensional electron gases formed in wells with two subbands displays ringlike structures when plotted in a density--magnetic-field diagram, due to the crossings of spin-split Landau levels…

Mesoscale and Nanoscale Physics · Physics 2010-03-10 Gerson J. Ferreira , Henrique J. P. Freire , J. Carlos Egues

We investigate the influence of an external magnetic field on spin phase relaxation of single electrons in semiconductor quantum dots induced by the hyperfine interaction. The basic decay mechanism is attributed to the dispersion of local…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Y. G. Semenov , K. W. Kim