Effects of Interface Resistance Asymmetry on Local and Non-local Magnetoresistance Structures

Spin injection and detection are very sensitive to the interface properties between ferromagnet and semiconductor. Because the interface properties such as a tunneling resistance and a polarization factor can be chosen independently between the injection and detection sides, the magnetic transport properties are considered to depend on the asymmetry of the two interfaces. We theoretically investigate the effect of the asymmetric interfaces of the injection side and the detection side on both the local and non-local magnetoresistance measurements. The results show the magnetoresistance ratio of local measurement structure has its maximum at the symmetric structure, and the effect of the asymmetry is very weak for the non-local measurement structure.