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Pure spin currents are measured in micron-wide channels of GaAs two-dimensional electron gas (2DEG). Spins are injected and detected using quantum point contacts, which become spin polarized at high magnetic field. High sensitivity to the…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 S. M. Frolov , A. Venkatesan , W. Yu , W. Wegscheider , J. A. Folk

Dynamic response of two-dimensional electron systems with spin-orbit interaction is studied theoretically on the basis of quantum kinetic equation, taking into account elastic scattering of electrons. The spin polarization and spin current…

Mesoscale and Nanoscale Physics · Physics 2007-06-19 O. E. Raichev

We measure nuclear and electron spin-polarized H and D densities of at least 10$^{19}\, cm^{-3}$ with $\sim$10 ns lifetimes, from the photodissociation of HBr and DI with circularly-polarized UV light pulses. This density is $\sim$6 orders…

We study the optical orientation of electron spins in GaAs/AlGaAs quantum wells for excitation in the growth direction and for in-plane excitation. Time- and polarization-resolved photoluminescence excitation measurements show, for resonant…

Mesoscale and Nanoscale Physics · Physics 2012-11-19 S. Pfalz , R. Winkler , N. Ubbelohde , D. Hägele , M. Oestreich

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

The spin-memory effect in the GaAs / InGaAs heterostructures with $\delta$<Mn> layer in GaAs barrier have been investigated. The effect consists in spin polarization of Mn atoms due to interaction with photogenerated spin-polarized holes.…

At the spin transition point of $\nu=2/3$ quantum Hall states, nuclear spins in a two-dimensional electron gas are polarized by an electric current. Using GaAs/AlGaAs double-quantum-well samples, we first observed the spatial diffusion of…

Mesoscale and Nanoscale Physics · Physics 2014-01-14 Minh-Hai Nguyen , Shibun Tsuda , Daiju Terasawa , Akira Fukuda , Yangdong Zheng , Anju Sawada

We have studied spin dephasing in a high-mobility two-dimensional electron system (2DES), confined in a GaAs/AlGaAs quantum well grown in the [110] direction, using the resonant spin amplification (RSA) technique. From the characteristic…

Materials Science · Physics 2013-05-30 M. Griesbeck , M. M. Glazov , E. Ya. Sherman , D. Schuh , W. Wegscheider , C. Schüller , T. Korn

The periodic optical orientation of electron spins in (In,Ga)As/GaAs quantum dots leads to the formation of electron spin precession modes about an external magnetic field which are resonant with the pumping periodicity. As the electron…

Mesoscale and Nanoscale Physics · Physics 2019-08-15 E. Evers , V. V. Belykh , N. E. Kopteva , I. A. Yugova , A. Greilich , D. R. Yakovlev , D. Reuter , A. D. Wieck , M. Bayer

Spin lasers leverage electron spin-polarisation to control photon polarisation, offering the potential for lower thresholds, rapid modulation, and all-optical data processing. We report successful spin injection into a commercial Vertical…

We present an investigation of the electron spin dynamics in an ensemble of singly-charged quantum dots subject to an external magnetic field and laser pumping with circularly polarized light. The spectral laser width is tailored such that…

Mesoscale and Nanoscale Physics · Physics 2018-12-05 Andreas Fischer , Eiko Evers , Steffen Varwig , Alex Greilich , Manfred Bayer , Frithjof B. Anders

We report on efficient spin injection in p-doped InGaAs/GaAs quantum-dot (QD) spin light emitting diode (spin-LED) under zero applied magnetic field. A high degree of electroluminescence circular polarization (Pc) ~19% is measured in…

Controlling the spin dynamics and spin lifetimes is one of the main challenges in spintronics. To this end, the study of the spin diffusion in two-dimensional electron gases (2DEGs) shows that when the Rashba and Dresselhaus spin-orbit…

Mesoscale and Nanoscale Physics · Physics 2021-04-14 I. R. de Assis , R. Raimondi , G. J. Ferreira

We study spin polarization in a split-gate quantum wire focussing on the effect of a realistic smooth potential due to remote donors. Electron interaction and spin effects are included within the density functional theory in the local spin…

Mesoscale and Nanoscale Physics · Physics 2008-04-04 M. Evaldsson , S. Ihnatsenka , I. V. Zozoulenko

We investigate the dynamic nuclear polarization process by frequently injecting polarized electron spins into a quantum dot. Due to the suppression of the direct dipolar and indirect electron-mediated nuclear spin interactions, by the…

Mesoscale and Nanoscale Physics · Physics 2016-07-26 Na Wu , Wenkui Ding , Anqi Shi , Wenxian Zhang

We investigate the dynamic polarization of nuclear spins in a nominally undoped GaAs/Al$_{0.35}$Ga$_{0.65}$As quantum well using two complementary experimental approaches: time-resolved Kerr rotation and optical orientation measurements of…

Mesoscale and Nanoscale Physics · Physics 2025-12-24 M. Kotur , D. Kudlacik , N. E. Kopteva , E. Kirstein , D. R. Yakovlev , K. V. Kavokin , M. Bayer

The classical drift diffusion (DD) model of spin transport treats spin relaxation via an empirical parameter known as the ``spin diffusion length''. According to this model, the ensemble averaged spin of electrons drifting and diffusing in…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Sandipan Pramanik , Supriyo Bandyopadhyay , Marc Cahay

Spatiotemporal spin dynamics under spin-orbit interaction is investigated in a (001) GaAs two-dimensional electron gas using magneto-optical Kerr rotation microscopy. Spin polarized electrons are diffused away from the excited position,…

Mesoscale and Nanoscale Physics · Physics 2021-01-20 Daisuke Iizasa , Asuka Aoki , Takahito Saito , Junsaku Nitta , Gian Salis , Makoto Kohda

A quantitative investigation of spin-pumping-induced spin-transport in n-GaAs was conducted at room temperature (RT). GaAs has a non-negligible spin orbit interaction, so that electromotive force due to the inverse spin Hall effect (ISHE)…

Materials Science · Physics 2015-06-23 Akiyori Yamamoto , Yuichiro Ando , Teruya Shinjo , Tetsuya Uemura , Masashi Shiraishi

We develop an extended pump-probe Faraday rotation technique to study the submicrosecond electron spin dynamics with picosecond time resolution in a wide range of magnetic fields. The electron spin dephasing time $T_2^*$ and the…

Mesoscale and Nanoscale Physics · Physics 2017-09-01 V. V. Belykh , E. Evers , D. R. Yakovlev , F. Fobbe , A. Greilich , M. Bayer