Magnetic field dependent excition transfer times in semimagnetic double quantum well structures

Abstract Tunnelling times are determined for the exciton transfer from the narrow to the wide well of CdTe/(Cd,Mn)Te asymmetric double quantum well structures with semimagnetic barrier and nonmagnetic wells by means of time resolved photoluminescence. A strong dependence of the tunnelling time on an external magnetic field up to 10 Tesla is found, which is attributed to the decrease of the barrier height. The tunnelling times vary between 900 ps and 35 ps. The important role of the excitonic interaction is pointed out.