Magnetic Anisotropies and (Ga,Mn)As-based Spintronic Devices


  • The authors would like to acknowledge the contributions of C. Rüster, S. Hümpfner, O. Rival, M. Grünewald, R. Giraud, G. M. Schott, J. Wenisch, K. Brunner, T. Borzenko, and V. Hock, who were instrumental in the realization of the experimental investigation leading to the results from our group presented in this work. We also wish to thank M. Sawicki and M. J. Schmidt for many useful discussions, as well as all our partners from the EU FENIKS consortium who have contributed greatly to our understanding of this material, and many of whose work is covered in this Review. Finally, we wish to acknowledge the financial support of the EU (projects FENIKS and SPINOSA), the DARPA Spins program, and the German BMBF (project 13N8284) and DFG (SFB 410).


In this Review, we discuss the rich anisotropic properties of the ferromagnetic semiconductor (Ga,Mn)As, and their implications in transport studies. We review the various sources and types of anisotropy seen in the material, discuss its magnetization reversal process, and demonstrate how basic transport properties, such as resistivity and Hall measurements, can be used as very sensitive tools to investigate the magnetization properties of the material. We also discuss how the magnetic anisotropy, coupled with large spin–orbit coupling, leads to an anisotropy in the transport density of states, which in turn leads to fundamentally novel behavior such as tunneling anisotropic magnetoresistance (TAMR).