Field dependence of the carrier occupation in double-quantum-well superlattices

The field-dependent carrier redistribution is calculated for double-quantum-well superlattices. Kinetic equations for the canonically transformed density matrix are solved analytically. At prevented crossings, when the levels of different quantum wells are aligned by the electric field, an appreciable field-induced carrier redistribution is predicted to occur. With increasing electric field, the subband populations change gradually and the levels exchange their role with respect to the ground state. This predicted carrier redistribution is compared with experimental results.