Tunneling anisotropic magnetoresistance: Creating a spin-valve-like signal using a single ferromagnetic semiconductor layer

This article reports on a spintronics device based on the ferromagnetic semiconductor (Ga,Mn)As. Our transport measurements on a Au/AlOx/(Ga,Mn)As tunnel junction yield the surprising result that it is possible to get a spin-valve-like signal using only one magnetic layer. The strong spin-orbit coupling in (Ga,Mn)As creates significant anisotropies in the density of states with respect to the magnetization orientation. This, together with a two-step magnetization reversal creates a bistable magnetoresistive device with properties unattainable in current metal based spin-valves.