Gated spin relaxation in (110)-oriented quantum wells

Growth, photoluminescence characterisation and time-resolved optical measurements of electron spin dynamics in (110)-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 170 K the electron spin relaxation rate in (110)-oriented wells shows a 100-fold reduction compared to equivalent (10 0)-oriented wells and also a 10-fold increase with applied electric field from 20 to 80 kV cm(-1). There is evidence for similar dramatic effects at 300 K. Spin relaxation is field independent below 20 kV cm(-1) reflecting quantum well asymmetry. The results indicate the achievability of voltage-gateable quantum well spin memory time longer than 10 ns at room temperature simultaneously with high electron mobility. (C) 2004 Elsevier B.V. All rights reserved.