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Related papers: Ultrafast Hole-Spin Dynamics in Optically Excited …

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We extend our recent result for the spin-relaxation time due to acoustic electron-phonon scattering in degenerate bands with spin mixing [New J. Phys. 18, 023012 (2015)] to include interactions with optical phonons, and present a numerical…

Materials Science · Physics 2017-08-23 Svenja Vollmar , David J. Hilton , Hans Christian Schneider

A relaxation-function theory for the dynamic spin susceptibility in the $t$--$J$ model is presented. By a sum-rule-conserving generalized mean-field approximation (GMFA), the two-spin correlation functions of arbitrary range, the staggered…

Strongly Correlated Electrons · Physics 2015-05-13 A. A. Vladimirov , D. Ihle , N. M. Plakida

The effect of nuclear spins in Fe/GaAs all-electrical spin-injection devices is investigated. At temperatures below 50 K, strong modifications of the non-local spin signal are found that are characteristic for hyperfine coupling between…

Mesoscale and Nanoscale Physics · Physics 2010-04-08 G. Salis , A. Fuhrer , S. F. Alvarado

We demonstrate that optical illumination strongly influences spin transport in n-type GaAs. Specifically, increasing the power density of optical spin pumping results in a significant expansion of the spin diffusion profile. A further means…

Materials Science · Physics 2008-10-27 J. -H. Quast , G. V. Astakhov , W. Ossau , L. W. Molenkamp , J. Heinrich , S. Hofling , A. Forchel

We study the doping evolution of spin excitations in a 1D Hubbard model and its downfolded spin Hamiltonians, by using exact diagonalization combined with cluster perturbation theory. In all models, we observe hardening (softening) of spin…

Strongly Correlated Electrons · Physics 2019-05-08 Ekaterina M. Pärschke , Yao Wang , Brian Moritz , Thomas P. Devereaux , Cheng-Chien Chen , Krzysztof Wohlfeld

We have employed time-dependent local-spin density theory to analyze the multipole spin and charge density excitations recently found in GaAs-AlGaAs quatum dots [C. Sch\"uller et al, Phys. Rev. Lett {\bf 80}, 2673 (1998)]. The overall…

Condensed Matter · Physics 2007-05-23 A. Emperador , M. Barranco , E. Lipparini , M. Pi , Ll. Serra

We have measured the electron spin relaxation rate and the integrated spin noise power in n-doped GaAs for temperatures between 4 K and 80 K and for doping concentrations ranging from 2.7 x 10^{-15} cm^{-3} to 8.8 x 10^{-16} cm^{-3} using…

Mesoscale and Nanoscale Physics · Physics 2013-05-29 M. Römer , H. Bernien , G. Müller , D. Schuh , J. Hübner , M. Oestreich

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

We report direct measurements of the spin-orbit interaction induced spin-splitting in a modulation-doped GaAs two-dimensional hole system as a function of anisotropic, in-plane strain. The change in spin-subband densities reveals a…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 B. Habib , J. Shabani , E. P. De Poortere , M. Shayegan , R. Winkler

In this paper we present an ab initio real-time analysis of free polarization decay and photon echo in extended systems. As a prototype material, we study bulk GaAs driven by ultra-short laser pulses of 10 fs (energy spread of 0.4 eV), with…

Materials Science · Physics 2022-06-15 M. D'Alessandro , D. Sangalli

We present a real-time abinitio description of optical orientation in bulk GaAs due to the coupling with an ultrashort circular polarized laser source. The injection of spin polarized electrons in the conduction band is correctly…

Materials Science · Physics 2020-10-07 Marco D'Alessandro , Davide Sangalli

We present a microscopic theory for transport of the spin polarized charge density wave with both electrons and holes in the $(111)$ GaAs quantum wells. We analytically show that, contradicting to the commonly accepted belief, the spin and…

Mesoscale and Nanoscale Physics · Physics 2013-11-27 M. Q. Weng , M. W. Wu

The population dynamics of dark and bright excitons in (In,Ga)As/GaAs quantum dots is studied by two-color pump-probe spectroscopy in an external magnetic field. With the field applied in Faraday geometry and at T<20 K, the dark excitons…

Mesoscale and Nanoscale Physics · Physics 2012-05-08 H. Kurtze , D. R. Yakovlev , D. Reuter , A. D. Wieck , M. Bayer

We demonstrate coherent optical control of a single hole spin confined to an InAs/GaAs quantum dot. A superposition of hole spin states is created by fast (10-100 ps) dissociation of a spin-polarized electron-hole pair. Full control of the…

Mesoscale and Nanoscale Physics · Physics 2012-01-09 T. M. Godden , J. H. Quilter , A. J. Ramsay , Yanwen Wu , P. Brereton , S. J. Boyle , I. J. Luxmoore , J. Puebla-Nunez , A. M. Fox , M. S. Skolnick

We examine spectral properties of doped holes dressed with surrounding spin cloud in the t-J model. These composite-hole excitations well characterize prominent band structures in the angle-resolved photoemission spectrum. In…

Strongly Correlated Electrons · Physics 2015-03-31 Takashi Otaki , Yuta Yahagi , Hiroaki Matsueda

In this work we derive simple closed-form expressions for the dynamical friction acting on black holes moving through ultralight (scalar field) dark matter, covering both non-relativistic and relativistic black hole speeds. Our derivation…

General Relativity and Quantum Cosmology · Physics 2022-04-27 Rodrigo Vicente , Vitor Cardoso

Magneto-optical techniques have become essential tools in spintronics, enabling the investigation of spin dynamics in the ultrafast regime. A key challenge in this field has been to accurately isolate the contributions to magneto-optical…

Spin orientation of photoexcited carriers and their energy relaxation is investigated in bulk Ge by studying spin-polarized recombination across the direct band gap. The control over parameters such as doping and lattice temperature is…

Materials Science · Physics 2013-07-24 F. Pezzoli , L. Qing , A. Giorgioni , G. Isella , E. Grilli , M. Guzzi , H. Dery

Carrier and spin recombination are investigated in p-type GaAs of acceptor concentration NA = 1.5 x 10^(17) cm^(-3) using time-resolved photoluminescence spectroscopy at 15 K. At low pho- tocarrier concentration, acceptors are mostly…

Materials Science · Physics 2017-04-05 F. Cadiz , D. Lagarde , P. Renucci , D. Paget , T. Amand , H. Carrère , A. C. H. Rowe , S. Arscott

A novel spin orientation mechanism - dynamic electron spin polarization has been recently suggested in Phys. Rev. Lett. $\mathbf{125}$, 156801 (2020). It takes place for unpolarized optical excitation in weak magnetic fields of the order of…

Mesoscale and Nanoscale Physics · Physics 2021-09-15 T. S. Shamirzaev , A. V. Shumilin , D. S. Smirnov , J. Rautert , D. R. Yakovlev , M. Bayer
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