Tunneling Magnetoresistance, Spin-Transfer and Spinorbitronics with (Ga,Mn)As
This chapter reviews some fundamental properties of tunneling spin-current, spin-transport of holes and spin-transfer of angular momenta in the valence band of magnetic III–V tunneling heterojunctions involving the ferromagnetic semiconductor (Ga,Mn)As. It discusses the modeling via advanced k·p kinetic exchange approach, the angular momentum transport in the valence band of semiconductors heterostructures. The chapter describes spin transfer torque experiments which have been demonstrated in the systems accounting for the conservation of the angular momenta of holes carried by the current for perpendicular-to-plane and in-plane current injection. It explores the skew tunneling and explains in detail the anomalous tunneling Hall Effect. The chapter demonstrates results of transport asymmetry implemented with advanced 30-band k·p methods adapted to the tunneling transport and using relevant wave function and wave current matching conditions that one compares to more standard k·p codes with excellent agreement. The general description of spin-polarized tunnel transport, including is fully described using standard k·p theory and Laudauer Buttiker formalism.