Spin-polarizing properties of the InAs/(AlSb)/GaMnSb/(AlSb)/InAs ferromagnetic resonant interband tunneling diode

We theoretically investigate the low-temperature spin-dependent current-voltage characteristics of the ferromagnetic resonant interband tunneling diode (FRITD). The simulations are based on a transmission formulation of the effective bond-orbital method (EBOM), which self-consistently includes both the electrostatic potential and the magnetic exchange interaction. Despite negligible spin splitting in the InAs emitter and collector regions, this type-II InAs/(AlSb)/GaMnSb/(AlSb)/InAs structure can function either as a source of spin-polarized electrons, whose polarity depends on the applied bias, or as a spin valve. For unpolarized emitter electrons, the spin polarization of carriers transmitted to the collector can be as high as ≈90%. We consider both thicker-well structures, in which the interband tunneling occurs primarily via light-hole-like states, and thinner-well devices whose transport is dominated by heavy-hole transitions. Since the maximum FRITD operating temperature is limited primarily by the Curie temperature in the GaMnSb hole quantum well, the same favorable device performance may be achievable at 77 K by employing the digital incorporation of Mn into the center of a GaSb hole well.