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Related papers: Hole spin polarization in GaAlAs:Mn structures

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We present quantitative measurements and calculations of the spin-orbit induced zero-magnetic-field spin-splitting in two-dimensional (2D) hole systems in modulation-doped GaAs (311)A quantum wells. The results show that the splitting is…

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

We investigate the dynamic nuclear polarization from the hyperfine interaction between nonequilibrium electronic spins and nuclear spins coupled to them in semiconductor nanostructures. We derive the time and position dependence of the…

Materials Science · Physics 2007-05-23 Ionel Tifrea , Michael E. Flatte

We present magnetic and tunnel transport properties of (Ga,Mn)As/(In,Ga)As/(Ga,Mn)As structure before and after adequate annealing procedure. The conjugate increase of magnetization and tunnel magnetoresistance obtained after annealing is…

Materials Science · Physics 2007-06-04 M. Elsen , H. Jaffres , R. Mattana , L. Thevenard , A. Lemaitre , J. -M. George

We show that an electric field parallel to the wavefronts of an electron-hole grating in a GaAs quantum well generates, via the electronic spin Hall effect, a spin grating of the same wave vector and with an amplitude that can exceed 1% of…

Mesoscale and Nanoscale Physics · Physics 2015-06-16 Ka Shen , G. Vignale

While the helical character of the edge channels responsible for charge transport in the quantum spin Hall regime of a two-dimensional topological insulator is by now well established, an experimental confirmation that the transport in the…

The magnetic order resulting from an indirect exchange between magnetic moments in the metallic phase of a Ga(1-x)Mn(x)As bilayered structure is studied "via" Monte Carlo simulation. The coupling mechanism involves a perturbative…

Materials Science · Physics 2007-05-23 A. Boselli , L. Loureiro da Silva , I. C. da Cunha Lima , A. Ghazali

In wide GaAs quantum wells where two electric subbands are occupied we apply a parallel magnetic field or increase the electron density to cause a crossing of the two $N=0$ Landau levels of these subbands and with opposite spins. Near the…

Mesoscale and Nanoscale Physics · Physics 2015-11-04 Yang Liu , S. Hasdemir , J. Shabani , M. Shayegan , L. N. Pfeiffer , K. W. West , K. W. Baldwin

A dc voltage biased II-VI semiconductor multiquantum well structure attached to normal contacts exhibits self-sustained spin-polarized current oscillations if one or more of its wells are doped with Mn. Without magnetic impurities, the only…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 L. L. Bonilla , R. Escobedo , M. Carretero , G. Platero

Spin-orbit coupling in semiconductors relates the spin of an electron to its momentum and provides a pathway for electrically initializing and manipulating electron spins for applications in spintronics and spin-based quantum information…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 V. Sih , R. C. Myers , Y. K. Kato , W. H. Lau , A. C. Gossard , D. D. Awschalom

We study the critical spin-polarization energy ($\alpha_{\rm C}$) above which fractional quantum Hall states in two-dimensional electron systems confined to symmetric GaAs quantum wells become fully spin-polarized. We find a significant…

Mesoscale and Nanoscale Physics · Physics 2014-09-23 Yang Liu , S. Hasdemir , A. Wójs , J. K. Jain , L. N. Pfeiffer , K. W. West , K. W. Baldwin , M. Shayegan

Hole spin relaxation time due to the hole-acoustic phonon scattering in GaAs quantum dots confined in quantum wells along (001) and (111) directions is studied after the exact diagonalization of Luttinger Hamiltonian. Different effects such…

Materials Science · Physics 2007-05-23 C. Lü , J. L. Cheng , M. W. Wu

In quasi two-dimensional (2D) hole systems with an effective spin j=3/2, heavy hole-light hole splitting results in a quantization of angular momentum perpendicular to the 2D plane. The spin polarization of quasi 2D hole systems due to an…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 R. Winkler

Hybrid structures synthesized from different materials have attracted considerable attention because they may allow not only combination of the functionalities of the individual constituents but also mutual control of their properties. To…

We demonstrate the epitaxial growth of optical-quality electrically-gated III-V ferromagnetic quantum structures. Photoluminescence spectroscopy reveals that initially unpolarized photoexcited holes in a GaAs quantum well become…

Materials Science · Physics 2007-05-23 R. C. Myers , A. C. Gossard , D. D. Awschalom

A simple model of circular polarization dependence on Mn delta-layer position in LED heterostructures with InGaAs/GaAs quantum well is proposed, being able to explain quite accurately recent fascinating experimental results [S.V. Zaitsev,…

Mesoscale and Nanoscale Physics · Physics 2009-02-23 D. V. Khomitsky

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

Magnetic $p$-$n$ junction diodes are fabricated to investigate spin-polarized electron transport. The injection of spin-polarized electrons in a semiconductor is achieved by driving a current from a ferromagnetic injector (Fe), into a bulk…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Peifeng Chen , Juergen Moser , Philipp Kotissek , Janusz Sadowski , Marcus Zenger , Dieter Weiss , Werner Wegscheider

Electrical spin injection from Fe into Al$_x$Ga$_{1-x}$As quantum well heterostructures is demonstrated in small (< 500 Oe) in-plane magnetic fields. The measurement is sensitive only to the component of the spin that precesses about the…

Condensed Matter · Physics 2009-11-10 J. Strand , B. D. Schultz , A. F. Isakovic , C. J. Palmstrom , P. A. Crowell

We calculate the critical density of the zero-temperature, first-order ferromagnetic phase transition in n-doped GaAs/AlGaAs quantum wells. We find that the existence of the ferromagnetic transition is dependent upon the choice of well…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 L. O. Juri , P. I. Tamborenea

The optical spin orientation effect in a GaAs/(Ga,Al)As quantum well containing a high-mobility 2D electron gas was found to be due to spin-polarized minority carriers, the holes. The observed oscillations of both the intensity and…

Mesoscale and Nanoscale Physics · Physics 2016-04-13 A. V. Koudinov , R. I. Dzhioev , V. L. Korenev , V. F. Sapega , Yu. G. Kusrayev