相关论文: L-valley Electron Spin Dynamics in GaAs
We observe millisecond spin-flip relaxation times of donor-bound electrons in high-purity n-GaAs . This is three orders of magnitude larger than previously reported lifetimes in n-GaAs . Spin-flip times are measured as a function of…
It has recently been suggested that two counter-propagating, circularly polarized, ultra-intense lasers can induce a strong electron spin polarization at the magnetic node of the electromagnetic field that they setup. We confirm these…
We demonstrate methods to locally control the spin rotation of moving electrons in a GaAs channel. The Larmor frequency of optically-injected spins is modulated when the spins are dragged through a region of spin-polarized nuclei created at…
In a GaAs single quantum dot, the relaxation time T_{1} between spin triplet and singlet states has been measured for the last few even number of electrons. The singlet-triplet energy separation E_{ST} is tuned as a control parameter for…
We report nearly complete preservation of "spin memory" between optical absorption and photoluminescence (PL) in nanometer slabs of GaSe pumped with 0.2 eV excess energy. At cryogenic temperatures, the initial degree of circular…
The spin dynamics of localized donor-bound electrons interacting with the nuclear spin ensemble in $n$-doped GaAs epilayers is studied using nuclear spin polarization by light with modulated circular polarization. We show that the observed…
We describe measurements of spin dynamics in the two-dimensional electron gas in GaAs/GaAlAs quantum wells. Optical techniques, including transient spin-grating spectroscopy, are used to probe the relaxation rates of spin polarization waves…
High degree of preservation of spin states during energy relaxation processes mediated by optical phonons is demonstrated in a single quantum dot. Optical-phonon resonance and relevant suppression of spin relaxation are clearly identified…
A spin-dependent emission of optically oriented electrons from p-GaAs(Cs,O) into vacuum was experimentally observed in a magnetic field normal to the surface. This phenomenon is explained within the model which takes into account the jump…
The spin relaxation time due to the electron-acoustic phonon scattering in GaAs quantum dots is studied after the exact diagonalization of the electron Hamiltonian with the spin-orbit coupling. Different effects such as the magnetic field,…
In p+ GaAs thin films, the effect of photoelectron degeneracy on spin transport is investigated theoretically and experimentally by imaging the spin polarization profile as a function of distance from a tightly-focussed light excitation…
We investigate exciton spin memory in individual InAs/GaAs self-assembled quantum dots via optical alignment and conversion of exciton polarization in a magnetic field. Quasiresonant phonon-assisted excitation is successfully employed to…
We report on the experimental evidence for a nanosecond time-scale spin memory based on nonradiative excitons. The effect manifests itself in magnetic-field-induced oscillations of the energy of the optically active (radiative) excitons.…
We review some of the newest findings on the spin dynamics of carriers and excitons in GaAs/GaAlAs quantum wells. In intrinsic wells, where the optical properties are dominated by excitonic effects, we show that exciton-exciton interaction…
We present a technique to calculate the spin relaxation of hot electrons during their energy thermalization in the Gamma-valley of zinc-blende semiconductors. The results of this model match recent experimental data and they can be used to…
The mechanisms for spin relaxation in semiconductors are reviewed, and the mechanism prevalent in p-doped semiconductors, namely spin relaxation due to the electron-hole exchange interaction, is presented in some depth. It is shown that the…
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…
Plasma turbulence is thought to be associated with various physical processes involved in solar flares, including magnetic reconnection, particle acceleration and transport. Using Ramaty High Energy Solar Spectroscopic Imager ({\it RHESSI})…
We present time-resolved Kerr rotation measurements of electron spin dynamics in a GaAs/AlGaAs heterojunction system that contains a high-mobility two-dimensional electron gas (2DEG). Due to the complex layer structure of this material the…
The exciton spin dynamics are investigated both experimentally and theoretically in two-monolayer-thick GaAs/AlAs quantum wells with an indirect band gap and a type-II band alignment. The magnetic-field-induced circular polarization of…