Gated spin relaxation in (1 1 0)-oriented quantum wells

Growth, photoluminescence characterisation and time-resolved optical measurements of electron spin dynamics in (1 1 0)-oriented GaAs/AlGaAs quantum wells are described. Conditions are given for MBE growth of good-quality quantum wells, judged by the width of low-temperature excitonic photoluminescence. At View the MathML source the electron spin relaxation rate in (1 1 0)-oriented wells shows a 100-fold reduction compared to equivalent (1 0 0)-oriented wells and also a 10-fold increase with applied electric field from 20 to View the MathML source. There is evidence for similar dramatic effects at View the MathML source. Spin relaxation is field independent below View the MathML source reflecting quantum well asymmetry. The results indicate the achievability of voltage-gateable quantum well spin memory time longer than View the MathML source at room temperature simultaneously with high electron mobility.