Tunneling magnetoresistance in CoFeB∕GaAs∕(Ga,Mn)As hybrid magnetic tunnel junctions

We reported the all electronic demonstration of spin injection and detection in the trilayers with hybrid structure of CoFeB∕GaAs∕(Ga,Mn)As (metal/insulator semiconductor) by probing the magnetoresistance at low temperature from 1.8to30K. Tunneling magnetoresistance (TMR) ratios of 3.8%, 4.7%, 2.9%, and 1.4% at 1.8, 10, 20, and 30K, respectively, were observed. Bias dependence of both the junction resistance and TMR ratio was studied systematically. Vhalf at which TMR drops to half of its maximum is 6.3mV, being much smaller compared to that observed in (Ga,Mn)As∕ZnSe∕Fe and (Ga,Mn)As∕AlAs∕MnAs hybrid structures, indicating lower Fermi energy of (Ga,Mn)As.