Characterization of spin-orbit fields in InGaAs quantum wells

摘要

Coherent electron spin dynamics in 10-nm-wide InGaAs/InAlAs quantum wells isstudied from 10 K to room temperature using time-resolved Kerr rotation. Thespin lifetime exceeds 1 ns at 10 K and decreases with temperature. By varyingthe spatial overlap between pump and probe pulses, a diffusive velocity isimprinted on the measured electron spins and a spin precession in thespin-orbit field is measured. A Rashba symmetry of the SOI is determined. Bycomparing the spatial precession frequency gradient with the spin decay rate,an upper limit for the Rashba coefficients $\alpha$ of 2$\times$10$^{-12}$ eVmis estimated.