Abstract: Based on wave-matching method, we investigate the tunneling magnetoresistance effect in ferromagnet-nonmagnetic impurity- ferromagnet system. The results show that existence of the molecular fields in two ferromagnets leads to the form of quasi-bound states under certain conditions. When the incident energy of electrons matches approximately the energy level of the quasi-bound states, the resonant tunneling occurs, which exhibit a peak in conductance. Nonmagnetic impurity and the effective masses of electrons in two ferromagnetic electrodes have remarkable effects on the behaviors of the conductance, including the amplitudes and the positions of the resonance peaks in conductance.

Key words: nonmagnetic impurity, magnetoresistance effect, tunneling junction