Electron spin dynamics in InGaAs quantum wells

Electron spin dynamics in strained In0.1Ga0.9As/Al0.4Ga0.6As quantum wells (QWs) on (100) and (110)-oriented substrates are investigated by time-resolved Faraday rotation. We find that the spin relaxation time in (110) QWs is 6 times longer than that in (100) QWs at low temperatures, which is strongly reduced by applying magnetic fields. The sign of g-factor is found positive and its magnitude decreases with increasing well width, in the well width range investigated here.