Spin helices in GaAs quantum wells: Interplay of electron density, spin diffusion, and spin lifetime

Room temperature spin diffusion in (110) GaAs/AlGaAs quantum wells

Transient spin grating experiments are used to investigate the electron spin diffusion in intrinsic (110) GaAs/AlGaAs multiple quantum well at room temperature. The measured spin diffusion length of optically excited electrons is about 4 μm at low spin density. Increasing the carrier density yields both a decrease of the spin relaxation time and the spin diffusion coefficient Ds.

Spin relaxation in GaAs(110) quantum wells

Ambipolar spin diffusion and D’yakonov-Perel’ spin relaxation in GaAs quantum wells

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...

Coupling of spin waves with charge- and spin-density excitations in spin-polarized quantum wells

The coupling of spin waves with chargeand spin-density waves is shown to be induced by a spin-dependent interaction in a quantum well, which is spin polarized by a dc magnetic field at an angle u to the symmetry axis. The mixing of the plasmonic and magnonic modes, which occurs for both intraand intersubband transitions, depends on the coupling constant of the spin-spin interaction, the tilt an...

MAGNETISATION AND ELECTRON SPIN RESONANCE STUDIES OF TETRAHEDRAL AMORPHOUS CARBON

The magnetisation and electron spin resonance (ESR) spectrum of two specimens of tetrahedral amorphous carbon (ta-C), deposited from a filtered cathodic arc, were measured over a wide temperature range. The magnetisation was found to consist of superparamagnetic, paramagnetic and diamagnetic contributions. The superparamagnetic contribution resembled that recently found in carbon prepared from ...