Subpicosecond spin relaxation in GaAsSb multiple quantum wells

K. C. Hall, S. W. Leonard, H. M. van Driel, A. R. Kost, E. Selvig, D. H. Chow
1999 Applied Physics Letters  
Spin relaxation times in GaAs x Sb 1Ϫx quantum wells are measured at 295 K using time-resolved circular dichroism induced by 1.5 m, 100 fs pulses. Values of 1.03 and 0.84 ps are obtained for samples with xϭ0 and 0.188, respectively. These times are Ͼ5 times shorter than those in InGaAs and InGaAsP wells with similar band gaps. The shorter relaxation times are attributed to the larger spin-orbit conduction-band splitting in the Ga͑As͒Sb system, consistent with the D'yakonov-Perel theory of spin
more » ... rel theory of spin relaxation ͓M. I. D'yakonov and V. I. Perel, Sov. Phys. JETP 38, 177 ͑1974͔͒. Our results indicate the feasibility of engineering an all-optical, polarization switch at 1.5 m with response time Ͻ250 fs.
doi:10.1063/1.125422 fatcat:7n7f6mr3fbdy3dw544ybvw2cq4