Conduction Band Spin Splitting in InxGa1-xAs/GaAs Quantum Wells

Optically detected spin resonance (ODSR) was used to obtain the effective g-values (g*) in type-I InxGa1-xAs/GaAs quantum wells. The resonances were detected on the excitonic quantum well luminescence that has an optical recombination time as short as 260 ps. Hence the present ODSR study addresses a regime far beyond the usual for magnetic resonance experiments, where the times of spin transitions and of carrier recombination dynamics are on a microsecond scale. The resonances, exhibiting an anisotropic g-tensor with the two components g∥* and g⊥*, are assigned to electric dipole-induced electron spin transitions. The g-values of the quantum wells differ from the bulk values, which is explained by strain and confinement.