CURRENT-INDUCED SPIN SEPARATION IN P-DOPED ASYMMETRIC DOUBLE-QUANTUM WELLS

In asymmetric double quantum wells, the ''spin'' splitting of the hole subbands at finite parallel momentum, due to the asymmetric potential, is related to a ''spin'' dependent delocalization of the wavefunction over the two wells. We show that the application of an electric field parallel to the interfaces in a p-doped asymmetric double quantum well can exploit such spin-dependent tunneling probability and separate carriers of opposite spins into the two wells, yielding a macroscopic magnetic moment of different magnitude and either the same or opposite direction in the two wells.