Related papers: Spin Injection and Relaxation in Ferromagnet-Semic…
The temperature dependence of electron spin coherence in singly negatively charged (In,Ga)As/GaAs quantum dots is studied by time-resolved Faraday rotation. The decoherence time T2 is constant on a microsecond scale for temperatures below…
Using a `standard' NMR spin-echo technique we determined the spin polarization of two-dimensional electrons, confined to GaAs quantum wells, from the hyperfine shift of Ga nuclei in the wells. Concentrating on the temperature and magnetic…
Measurements and modeling of electron spin transport and dynamics are used to characterize hyperfine interactions in Fe/GaAs devices with $n$-GaAs channels. Ga and As nuclei are polarized by electrically injected electron spins, and the…
We calculate the current spin polarisation and the interface resistance of Fe/GaAs and Fe/ZnSe (001) spin injection junctions from first principles, including also the possibility of a Schottky barrier. From our results of interface…
A comparison is made between the degree of spin polarization of electrons excited by one- and two-photon absorption of circularly polarized light in bulk zincblende semiconductors. Time- and polarization-resolved experiments in…
Sustaining exotic quantum mechanical phases at high temperatures is a long-standing goal of condensed matter physics. Among them, half-metals are spin-polarized conductors that are essential for realizing room-temperature spin current…
A fully microscopic theory of electron spin relaxation by the D'yakonov-Perel' type spin-orbit coupling is developed for a semiconductor quantum well with a magnetic field applied in the growth direction of the well. We derive the Bloch…
Thermodynamic flunctuations in BaFe2As2 is addressed with a first-principles formulation of the Helmholtz energy by accounting for the mixture of various electronic states each distinguished by different spin orientation distributions. We…
Optical orientation of carrier spins by circularly polarized light is the basic concept and tool of spin physics in semiconductors. We study the optical orientation of electrons and holes in a crystal of the…
We present theoretical aspects of spin polarized two dimensional electron gas (SP2DEG) which can be achieved in doped semimagnetic quantum wells. This original model system has been recently studied by magneto Raman scattering experiments…
The nonlocal spin resistance is measured as a function of temperature in a Fe/GaAs spin-injection device. For nonannealed samples that show minority-spin injection, the spin resistance is observed up to room temperature and decays…
We report on experiments in which a spin-polarized current is injected from a $GaMnAs$ ferromagnetic electrode into a $GaAs$ quantum well through an AlAs barrier. The resulting spin polarization in the GaAs well is detected by measuring how…
We directly measure the hole spin lifetime in ferromagnetic GaMnAs via time- and polarization-resolved spectroscopy. Below the Curie temperature Tc, an ultrafast photoexcitation with linearly-polarized light is shown to create a…
Spin dynamics of two-dimensional electron gas confined in an asymmetrical quantum well is studied theoretically in the regime where the scattering frequency is comparable with the spin precession frequency due to the conduction band spin…
In the field of spin-controlled semiconductor lasers, massive effort has been focused upon materials with long spin relaxation times (~ns). In contrast, we demonstrate room-temperature spin-polarized ultrafast pulsed lasing in InGaAs…
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…
The helicity of a circularly polarized light beam may be determined by the spin direction of photo-excited electrons in a III-V semiconductor. We present a theoretical demonstration how the direction of the ensuing electron spin…
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…
Spin polarization measurements were performed in three 2D Electron Gases in GaAs with densities n = 9.1, 7.2 and 6.5 x10^10 cm-2, in the quantum Hall regime. Full spin polarization at v = 1 surrounded by rapid depolarization due to Skyrmion…
We suggest a new spin orientation mechanism for localized electrons: $dynamic~electron~spin~polarization~provided~by~nuclear~spin~fluctuations$. The angular momentum for the electrons is gained from the nuclear spin system via the hyperfine…