Electrical control of magnetic domains has the potential to overcome key challenges to the development of new non-volatile and down-scalable logic and memory devices. We study the spin-orbit torque induced by an unpolarized electric current in the dilute ferromagnetic semiconductor, (Ga,Mn)As. The current-induced torque (CIT) is modeled as the interaction between the uniform magnetization and an effective magnetic field representing the non-equilibrium carrier spin-polarization. We calculate the current-induced field (CIF) using the Kubo linear-response formalism for a broad range of material parameters. We find that the CIF is composed of a dominant term due to the inverse spin galvanic effect and a small component which is dependent on the relative orientation of the current, magnetization, and crystal axes. In conjunction with experimental studies, we investigate the magnetization dynamics using the phenomenological Landau-Lifschitz-Gilbert equation. The study of (Ga,Mn)As opens the door to a comprehensive theory of CITs in uniform magnetic semiconductors.
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Authors
Erin K. Vehstedt
Texas A\&M University, USA; Institute of Physics, ASCR, CZ
Liviu P. Zarbo
Institute of Physics, ASCR, CZ
Karel Vyborny
University at Buffalo-SUNY; Institute of Physics ASCR, SUNY Buffalo, USA; Institute of Physics, ASCR, CZ
Hidekazu Kurebayashi
University of Cambridge, UK
Pierre Roy
Hitachi Cambridge Laboratory, UK
Joerg Wunderlich
Hitachi Cambridge Laboratory, UK; Institute of Physics, ASCR, CZ
Andrew J. Ferguson
University of Cambridge, University of Cambridge, UK
Tomas Jungwirth
Institute of Physics, Academy of Sciences Czech Republic, Institue of Physics, ASCR, CZ; University of Nottingham, UK
Jairo Sinova
Texas A\&M University, USA; Institute of Physics, ASCR, CZ, Department of Physics, Texas A\&M University, College Station, Texas 77843-4242, USA
