Optical detection of zero-field spin precession of high mobility two-dimensional electron gas in a gated GaAs/AlGaAs quantum well

摘要

We investigated the effective magnetic field induced by spinorbit interaction in a gated modulation-doped GaAs/AlGaAs quantum well (QW) structure. We measured the precession of the optically injected electron spins at zero magnetic field by a time-resolved Kerr rotation (TRKR) technique as a function of the gate voltage V_g. The V_g-dependence of the effective magnetic field extracted from the TRKR data was quantitatively analyzed by considering both Rashba and Dresselhaus spinorbit interaction in a Monte Carlo simulation. With the Dresselhaus spinorbit coupling parameter γ and the scattering time as fitting parameters, we reproduced the experimental TRKR data, from which we estimated γ～13 eV ~3.