We report theoretical and experimental studies of ambipolar spin diffusion in a semiconductor. A circularly polarized laser pulse is used to excite spin-polarized carriers in a GaAs multiple quantum-well sample at 80 K. Diffusion of electron and spin densities is simultaneously measured using a spatially and temporally resolved pump-probe technique. Two regimes of diffusion for spin-polarized e...

We present a detailed description of spin injection and detection in Fe/AlxGa1−xAs/GaAs heterostructures for temperatures from 2 to 295 K. Measurements of the steady-state spin polarization in the semiconductor indicate three temperature regimes for spin transport and relaxation. At temperatures below 70 K, spinpolarized electrons injected into quantum well structures form excitons, and the spi...

The dependence on spin-lattice (T1) relaxation of the first-harmonic absorption EPR signal (V'1) detected in phase quadrature with the Zeeman modulation has been investigated both theoretically and experimentally for nitroxide spin labels. Spectral simulations were performed by iterative solution of the Bloch equations that contained explicitly both the modulation and microwave magnetic fields ...

We investigate effects of spin-orbit splitting on electronic transport in a spin valve consisting of a large quantum dot defined on a two-dimensional electron gas with two ferromagnetic contacts. In the presence of both structure and bulk inversion asymmetry a giant anisotropy in the spin-relaxation times has been predicted. We show how such an anisotropy affects the electronic transport proper...

The spin locking method known from NMR is shown to be useful also in ESR for investigating spin lattice relaxation problems and "slow" motions, e. g. questions of energy transfer by triplet states in organic molecular crystals, and probing of nuclear quadrupolar splittings even smaller than the ESR line width at zero magnetic field. Optically detected ESR spin locking experiments for isolated t...

Spintronics attracts much attention because of the potential to build novel spin-based devices which are superior to nowadays charge-based microelectronic devices. Silicon, the main element of microelectronics, is promising for spin-driven applications. Understanding the details of the spin propagation in silicon structures is a key for building novel spin-based nanoelectronic devices. We inves...

Through spin exchange optical pumping it is possible to achieve upwards of nuclear spin polarization in Xe with an NMR signal enhancement of some orders of magnitude over typical thermal signals Hyperpolarized Xe has thus found application in several leading edge technologies At T and K the characteristic relaxation time of enriched polycrystalline Xe Xe Xe is well over hrs su cient for long te...

The spin lattice relaxation of I = 3/2 quadrupolar spin system due to domain walls in order-disorder ferroelectrics has been studied and a general method is proposed for the measurement of domain width in nano ferroelectrics. Based on the fact that electric polarization undergoes spiral orientation as one moves from one domain to the other, it is assumed that at low temperatures the spins at an...