Fachgruppe Nanostrukturierte Materialien    

We study the transport characteristics of all II–VI semiconductor resonant tunneling diodes made from the (Zn,Mn,Be)Se material system and with a quantum well of dilute magnetic material. The current–voltage characteristics of these devices exhibit a normal resonant tunneling diode resonance at zero external magnetic field. When a field is applied, the resulting spin splitting of the levels in the quantum well splits the transmission resonance into two separate peaks that move apart with increasing field. We interpret this as evidence that the tunneling is taking place through spin polarized levels. This device could therefore be viewed as a first step towards the demonstration of a voltage controlled spin filter.