Spin-dependent phenomena in (Ga,Mn) As heterostructures

A model for spin-dependent tunneling in semiconductor heterostructures, which combines a multi-orbital empirical tight-binding approach with a Landauer-Buttiker formalism, is presented. Using this approach we explain several phenomena observed in modulated structures of (Ga,Mn)As, i.e., large values of the electron current spin polarization in magnetic Esaki-Zener diode and the high tunneling magnetoresistance ratio. Next, the relevance of this theory to assess the tunneling anisotropic magnetoresistance effect is studied. The results of applying the tight-binding model to describe the recently observed interlayer exchange coupling in (Ga,Mn)As-based superlattices are also shown.