Giant anti-Stokes photoluminescence from semimagnetic heterostructures

Abstract

A giant anti-Stokes photoluminescence is observed at low excitation densities on specially designed semimagnetic II--VI asymmetric double quantum well structures by applying an external magnetic field. The signal is due to a two-step absorption process, mediated by a long-living spatially indirect exciton, created via rapid electron tunneling from the primarily excited direct exciton state.