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Related papers: Optical spin orientation and depolarization in Ge

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We investigate spin polarized electron transport in ultra-thin Si-Core/Ge-Shell and Ge-Core/Si-Shell nanowire system using semi-classical Monte Carlo simulation method. Depolarization of electron's spin occurs in nanowire mainly due to…

Mesoscale and Nanoscale Physics · Physics 2016-04-13 Bhupesh Bishnoi , Bahniman Ghosh

Carrier spins in semiconductor nanocrystals are promising candidates for quantum information processing. Using a combination of time-resolved Faraday rotation and photoluminescence spectroscopies, we demonstrate optical spin polarization…

We have studied spin dephasing and spin diffusion in a high-mobility two-dimensional electron system, embedded in a GaAs/AlGaAs quantum well grown in the [110] direction, by a two-beam Hanle experiment. For very low excitation density, we…

Mesoscale and Nanoscale Physics · Physics 2011-07-01 R. Völkl , M. Griesbeck , S. A. Tarasenko , D. Schuh , W. Wegscheider , C. Schüller , T. Korn

Light polarization can conveniently encode information. Yet, the ability to steer polarized optical fields is notably demanding but crucial to develop practical methods for data encryption and to gather fundamental insights into…

We use semiclassical Monte Carlo approach along with spin density matrix calculations to model spin polarized electron transport. The model is applied to germanium nanowires and germanium two dimensional channels to study and compare spin…

Mesoscale and Nanoscale Physics · Physics 2011-06-23 Ashish Kumar , Bahniman Ghosh

The optical orientation of the exciton spin in an ensemble of self-organized cubic GaN/AlN quantum dots is studied by time-resolved photoluminescence. Under a polarized quasi-resonant excitation, the luminescence linear polarization…

Other Condensed Matter · Physics 2009-11-13 D. Lagarde , A. Balocchi , H. Carrere , P. Renucci , T. Amand , X. Marie , S. Founta , H. Mariette

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

We present a comprehensive theory of the circularly polarized luminescence and its dependence on strain in spin-polarized Si and Ge. Symmetries of wavefunctions and interactions are used to derive concise ratios between intensities of the…

Materials Science · Physics 2013-03-12 Pengke Li , Dhara Trivedi , Hanan Dery

We have applied the photoexcited muon spin spectroscopy technique (photo-$\mu$SR) to intrinsic germanium with the goal of developing a new method for characterizing excess carrier kinetics in a wide range of semiconductors. Muon spin…

Materials Science · Physics 2019-10-02 K. Yokoyama , J. S. Lord , P. W. Mengyan , M. R. Goeks , R. L. Lichti

We study the transport of spin polarized electrons in n-GaAs using spatially resolved continuous wave Faraday rotation. From the measured steady state distribution, we determine spin relaxation times under drift conditions and, in the…

Materials Science · Physics 2007-05-23 M. Beck , C. Metzner , S. Malzer , G. H. Döhler

The photon spin is an important resource for quantum information processing as is the electron spin in spintronics. However, for subwavelength confined optical excitations, polarization as a global property of a mode cannot be defined.…

Optics · Physics 2018-12-11 Enno Krauss , Gary Razinskas , Dominik Köck , Swen Grossmann , Bert Hecht

Germanium-based alloys hold great promise for future spintronics applications, due to their potential for integration with conventional Si-based electronics. Mn5Ge3 exhibits strong ferromagnetism up to the Curie temperature Tc~295K. We use…

Strongly Correlated Electrons · Physics 2009-11-10 R. P. Panguluri , Changgan Zeng , H. H. Weitering , J. M. Sullivan , S. C. Erwin , B. Nadgorny

We use optical transient-grating spectroscopy to measure spin diffusion of optically oriented electrons in bulk, semi-insulating GaAs(100). Trapping and recombination do not quickly deplete the photoexcited population. The spin diffusion…

Materials Science · Physics 2011-11-01 C. P. Weber , Craig A. Benko , Stanley C. Hiew

We have studied the possibly half metallic Co2FeSi full Heusler alloy by means of spin- and time-resolved photoemission spectroscopy. For excitation, the second and fourth harmonic of femtosecond Ti:sapphire lasers were used, with photon…

Materials Science · Physics 2016-08-16 J. -P. Wüstenberg , M. Cinchetti , M. Sánchez Albaneda , M. Bauer , M. Aeschlimann

By direct measurements of the complex optical conductivity $\sigma(\nu)$ of FeSi we have discovered a broad absorption peak centered at frequency $\nu_{0}(4.2 K) \approx 32 cm^{-1}$ that develops at temperatures below 20 K. This feature is…

Strongly Correlated Electrons · Physics 2015-03-19 V. V. Glushkov , B. P. Gorshunov , E. S. Zhukova , S. V. Demishev , A. A. Pronin , N. E. Sluchanko , S. Kaiser , M. Dressel

We present experimental and theoretical results on hole-spin dynamics in bulk GaAs after ultrafast optical excitation. The experimental differential transmission are compared with a dynamical calculation of the momentum-resolved hole…

Materials Science · Physics 2010-12-21 Michael Krauss , David J. Hilton , Hans Christian Schneider

We present a complete description of spin injection and detection in Fe/Al_xGa_{1-x}As/GaAs heterostructures for temperatures from 2 to 295 K. Measurements of the steady-state spin polarization in the semiconductor indicate three…

Materials Science · Physics 2009-11-10 C. Adelmann , X. Lou , J. Strand , C. J. Palmstrom , P. A. Crowell

The carrier spin dynamics in ZnO is investigated by time-resolved optical orientation experiments. We evidence a clear circular polarization of the donor-bound exciton luminescence in both ZnO epilayer and non-intentionally doped bulk ZnO.…

Other Condensed Matter · Physics 2008-04-16 D. Lagarde , A. Balocchi , P. Renucci , H. Carrère , F. Zhao , T. Amand , X. Marie , Z. X. Mei , X. L. Du , Q. K. Xue

We study the effect of the impurity density on lifetimes and relaxation lengths of electron spins in the presence of a static electric field in a n-type GaAs bulk. The transport of electrons and the spin dynamics are simulated by using a…

Other Condensed Matter · Physics 2012-06-19 Stefano Spezia , Dominique Persano Adorno , Nicola Pizzolato , Bernardo Spagnolo

To establish a correlation between the spin diffusion, the spin lifetime, and the electron density, we study, employing time-resolved magneto-optical Kerr effect microscopy, the spin polarization evolution in low-dimensional GaAs…

Mesoscale and Nanoscale Physics · Physics 2022-08-17 S. Anghel , A. V. Poshakinskiy , K. Schiller , G. Yusa , T. Mano , T. Noda , M. Betz