Strain-induced enhancement of spin relaxation times in [110] and [111] grown quantum wells

We derive the strain-dependent Hamiltonian of the conduction band for semiconductor quantum wells grown along [110] and [111] directions. We propose and demonstrate theoretically that by properly controlling the strain of InGaAs/InP quantum wells, the spin relaxation from the Dyakonov-Perel mechanism can be suppressed in [110] and [111] quantum wells. The spin relaxation time can be enhanced by more than one order of magnitude at an optimal strain for a given well width.