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We find that photoexcited electrons in an n-GaAs epilayer rapidly (< 50 ps) spin-polarize due to the proximity of an epitaxial ferromagnetic metal. Comparison between MnAs/GaAs and Fe/GaAs structures reveals that this coherent spin…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 R. J. Epstein , I. Malajovich , R. K. Kawakami , Y. Chye , M. Hanson , P. M. Petroff , A. C. Gossard , D. D. Awschalom

We develop a Monte Carlo model to study injection of spin-polarized electrons through a Schottky barrier from a ferromagnetic metal contact into a non-magnetic low-dimensional semiconductor structure. Both mechanisms of thermionic emission…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Min Shen , Semion Saikin , Ming-C. Cheng

In this letter, we show efficient electrical spin injection into a SiGe based \textit{p-i-n} light emitting diode from the remanent state of a perpendicularly magnetized ferromagnetic contact. Electron spin injection is carried out through…

Materials Science · Physics 2009-11-13 L. Grenet , M. Jamet , P. Noé , V. Calvo , J. -M. Hartmann , L. E. Nistor , B. Rodmacq , S. Auffret , P. Warin , Y. Samson

We study light-induced nuclear spin-polarization in a thin film of Ga1-xMnxAs (x 0.04), a dilute ferromagnetic semiconductor, grown on a GaAs substrate. High-field inductively-detected Ga-71 NMR was performed with samples immersed in…

Experiments suggest that nuclear spins play a significant role in the quantum Hall effect (QHE) near integer and fractional QHE spin transitions, but many of these phenomena still remain to be understood. Here we study theoretically the…

Mesoscale and Nanoscale Physics · Physics 2026-02-03 Haotian Zhou , Yuli Lyanda-Geller

We propose to use the lateral interface between two regions with different strengths of the spin-orbit interaction(s) to spin-polarize the electrons in gated two dimensional semiconductor heterostructures. For a beam with a non zero angle…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 M. Khodas , A. Shekhter , A. M. Finkel'stein

The parallel field of a full spin polarization of the electron gas in a \Gamma8 conduction band of the HgTe quantum well was obtained from the magnetoresistance by three different ways in a zero and quasi-classical range of perpendicular…

Mesoscale and Nanoscale Physics · Physics 2015-05-28 M. V. Yakunin , A. V. Suslov , S. M. Podgornykh , S. A. Dvoretsky , N. N. Mikhailov

Semiconductor quantum dots provide a spin-coupled system of an electron and nuclei via enhanced hyperfine interaction. We showed that the nuclear spin polarization in single quantum dots can have three stable branches under a longitudinal…

Mesoscale and Nanoscale Physics · Physics 2020-07-01 Sota Yamamoto , Reina Kaji , Hirotaka Sasakura , Satoru Adachi

Using a conventional Hall-bar geometry with a micro-metal strip on top of the surface, we demonstrate an electrical coherent control of nuclear spins in an AlGaAs/GaAs semiconductor heterostructure. A breakdown of integer quantum Hall (QH)…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 H. Takahashi , M. Kawamura , S. Masubuchi , K. Hamaya , T. Machida , Y. Hashimoto , S. Katsumoto

We demonstrate the electrical injection and detection of spin-polarized electrons in the Co2FeSi/GaAs hybrid system using lateral transport structures. Spin valve signatures and characteristic Hanle curves are observed both in the nonlocal…

Mesoscale and Nanoscale Physics · Physics 2015-06-15 Pawel Bruski , Yori Manzke , Rouin Farshchi , Oliver Brandt , Jens Herfort , Manfred Ramsteiner

The hyperfine field from dynamically polarized nuclei in n-GaAs is very spatially inhomogeneous, as the nu- clear polarization process is most efficient near the randomly-distributed donors. Electrons with polarized spins traversing the…

Disordered Systems and Neural Networks · Physics 2015-10-16 N. J. Harmon , T. A. Peterson , C. C. Geppert , S. J. Patel , C. J. Palmstrøm , P. A. Crowell , M. E. Flatté

A self-consistent calculation of the electronic properties of GaAlAs:Mn magnetic semiconductor quantum well structures is performed including the Hartree term and the sp-d exchange interaction with the Mn magnetic moments. The spin…

Materials Science · Physics 2009-10-31 A. Ghazali , I. C. da Cunha Lima , M. A. Boselli

The mesoscopic spin system formed by the 10E4-10E6 nuclear spins in a semiconductor quantum dot offers a unique setting for the study of many-body spin physics in the condensed matter. The dynamics of this system and its coupling to…

Mesoscale and Nanoscale Physics · Physics 2013-01-11 Bernhard Urbaszek , Xavier Marie , Thierry Amand , Olivier Krebs , Paul Voisin , Patrick Maletinsky , Alexander Hogele , Atac Imamoglu

Alloying effects by T=Mn,Co,Ni-substitution on FeS$_2$ have been investigated using density-functional calculations. The ferromagnetic alloys Fe$_{1-x}$T$_x$S$_2$ have been investigated for concentrations…

Materials Science · Physics 2015-12-16 Abdesalem Houari , Peter E. Blöchl

First-principles investigations of the structural, electronic and magnetic properties of Cr-doped AlN/GaN (0001) heterostructures reveal that Cr segregates into the GaN region, that these interfaces retain their important half-metallic…

Materials Science · Physics 2009-11-10 J. E. Medvedeva , A. J. Freeman , X. Y. Cui , C. Stampfl , N. Newman

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

An experimental protocol is presented that allows the entropy generated by spin-transfer to be measured. The effect of a strong spin-polarized current injected on a ferromagnetic nanostructure is investigated with focusing on the…

Mesoscale and Nanoscale Physics · Physics 2008-08-05 J. -E. Wegrowe , Q. Anh Nguyen , T. L. Wade

Nuclear spin coherence and relaxation dynamics of all constituent isotopes of an n-doped CdTe/(Cd,Mg)Te quantum well structure are studied employing optically detected nuclear magnetic resonance. Using time-resolved pump-probe Faraday…

Mesoscale and Nanoscale Physics · Physics 2019-04-04 E. Evers , T. Kazimierczuk , F. Mertens , D. R. Yakovlev , G. Karczewski , T. Wojtowicz , J. Kossut , M. Bayer , A. Greilich

The polarization of conduction electron spins due to an electrical current is observed in strained nonmagnetic semiconductors using static and time-resolved Faraday rotation. The density, lifetime, and orientation rate of the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Y. Kato , R. C. Myers , A. C. Gossard , D. D. Awschalom

Current-induced electron spin polarization is shown to produce nuclear hyperpolarization through dynamic nuclear polarization. Saturated fields of several millitesla are generated upon the application of electric field over a timescale of a…

Mesoscale and Nanoscale Physics · Physics 2014-10-31 C. J. Trowbridge , B. M. Norman , Y. K. Kato , D. D. Awschalom , V. Sih