Effect of electron-hole interaction on electron spin relaxation in GaAs/AlGaAs quantum wells at room temperature

Abstract

We investigated electron spin relaxation with respect to the spatial electron-hole separation in GaAs/AlGaAs quantum wells at room temperature. The polarization dependent time-resolved photoluminescence method was used to measure the electron spin relaxation time by applying an electric field perpendicular to the quantum wells. The spin relaxation time had a strong electric field dependence and largely increased with an increase in the spatial electron-hole separation. These results cannot be explained by only the D'yakonov-Perel process, which has often been considered the cause of spin relaxation. We discuss the possible mechanisms that cause the spin relaxation by taking into account the electron-hole exchange interaction. © 2000 American Institute of Physics.