High Temperature Gate Control of Quantum Well Spin Memory

Time-resolved optical measurements in (110)-oriented GaAs/AlGaAs quantum wells show a tenfold increase of the spin-relaxation rate as a function of applied electric field from 20 to $80\mathrm{k}\mathrm{V}{\mathrm{c}\mathrm{m}}^{-1}$ at 170 K and indicate a similar variation at 300 K, in agreement with calculations based on the Rashba effect. Spin relaxation is almost field independent below $20\mathrm{k}\mathrm{V}{\mathrm{c}\mathrm{m}}^{-1}$ reflecting quantum well interface asymmetry. The results indicate the achievability of a voltage-gateable spin-memory time longer than 3 ns simultaneously with a high electron mobility.