Magnetic field mediated anti-Stokes luminescence of semimagnetic ADQW structures

A giant anti-Stokes PL (ASPL) was observed in a specially designed II-VI as ymmetric DQW made up of a magnetic and a nonmagnetic well by applying an ex ternal magnetic field. ASPL from the high energy well was generated by exci ting the lower energy well. The ASPL intensity is of the same order of magn itude as the Stokes band. Evidence is given for a two-step absorption (TSA) process. As intermediate states of the TSA act the long living spatially i ndirect excitons. (C) 1998 Elsevier Science B.V. All rights reserved.