Spin dependent transport in diluted magnetic semiconductor/superconductor tunnel junctions

• Transport properties of DMS/SC/DMS double tunneling junctions have been investigated in the BTK model.
• TMR dependence on barrier strength, spin polarization of DMS layers and the SC barrier parameters has been studied.
• An oscillatory behavior with the quasi-particle energy has been observed in the conductance spectrum.

A modification of Blonder–Tinkham–Klapwijk (BTK) model is proposed to describe transport properties of diluted magnetic semiconductor (DMS)/superconductor(SC)/DMS double tunneling junctions. Coherent spin-polarized transport is studied by taking into account the Andreev reflection on spatial variation of SC barrier parameters in the heterostructure. It is shown that the conductance spectrum exhibits an oscillatory behavior with quasi-particle energy, and the oscillation amplitude is reduced with increasing temperature. We also examine the dependence of tunneling magnetoresistance (TMR) on the barrier strength (κκ) and spin polarization (P) of two DMS layers. Our results show that TMR decreases with increasing temperature and barrier strength, which may be useful in designing the nano spin-valve devices based on DMS and SC materials.