Spin-polarized transport in ferromagnetic semiconductor/ferromagnetic d-wave superconductor tunnel junction

Abstract

By solving a self-consistent equation for the d-wave superconducting gap and the magnetization, and applying an extended Blonder-Tinkham-Klapwijk approach, we study the spin-polarized quasiparticle transport coefficients and the differential conductance in ferromagnetic semiconductor/ferromagnetic d-wave superconductor junction. It is shown that (1) the exchange energy h0 in the ferromagnetic d-wave superconductor may make the zero-bias conductance peak and energy gap peak split into two peaks, and the energy difference between the two splitting peaks is equal to 2h0; (2) the exchange energy hFS in the ferromagnetic semiconductor can decrease the height of the two peaks resulting from splitting of the zero-bias conductance peak. For the splitting of the energy gap conductance peak, however, with hFS increased the left-hand peak is lowered and the right-hand peak is raised in the parallel configuration, but the left-hand peak is raised and the right-hand peak is lowered in the antiparallel configuration.