Universality Classes for Domain Wall Motion in the Ferromagnetic Semiconductor (Ga,Mn)As

• DOI: 10.1126/science.1145516
• Publication Date: 2007-09-20T21:24:10Z
• Authors: M. Yamanouchi; J. Ieda; F. Matsukura; S. E. Barnes; S. Maekawa; H. Ohno
• Keywords: Magnetic semiconductor; Subthreshold conduction

Magnetic domain wall motion induced by magnetic fields and spin-polarized electrical currents is experimentally well established. A full understanding of the underlying mechanisms, however, remains elusive. For ferromagnetic semiconductor (Ga,Mn)As, we have measured compared such motions in thermally activated subthreshold, or "creep," regime, where velocity obeys an Arrhenius scaling law. Within this law, clearly different exponents current field reflect universality classes, showing that drive mechanisms are fundamentally different.