Spin-dependent transport properties in GaMnAs-based spin hot-carrier transistors

The authors have investigated the spin-dependent transport properties of GaMnAs-based three-terminal semiconductor spin hot-carrier transistor (SSHCT) structures. The emitter-base bias voltage V-EB dependence of the collector current I-C, emitter current I-E, and base current I-B shows that the current transfer ratio alpha (=I-C/I-E) and the current gain beta (=I-C/I-B) are 0.8-0.95 and 1-10, respectively, which means that GaMnAs-based SSHCTs have current amplification capability. In addition, the authors observed an oscillatory behavior of the tunneling magnetoresistance ratio with the increasing bias, which can be explained by the resonant tunneling effect in the GaMnAs quantum well.