Adiabatic spin-transfer-torque-induced domain wall creep in a magnetic metal

• Published in: Nature physics Vol. 12; no. 4; pp. 333 - 336
• Main Authors: DuttaGupta, S., Fukami, S., Zhang, C., Sato, H., Yamanouchi, M., Matsukura, F., Ohno, H.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.04.2016; Nature Publishing Group
• Subjects: 639/766/119/1001; 639/766/530/2803; 639/925/357/997; Adiabatic flow; Atomic; Classical and Continuum Physics; Complex Systems; Condensed Matter Physics; Creep (materials); Disorders; Domain walls; Elastic systems; letter; Magnetic domains; Magnetic fields; Magnetism; Mathematical and Computational Physics; Metals; Molecular; Optical and Plasma Physics; Physics; Statistics; Theoretical; Walls
• ISSN: 1745-2473; 1745-2481
• DOI: 10.1038/nphys3593

The creep motion of domain walls in magnetic metals can belong to different universality classes depending on whether they are driven by magnetic fields or spin-polarized currents. The dynamics of elastic interfaces is a general field of interest in statistical physics, where magnetic domain wall has served as a prototypical example. Domain wall ‘creep’ under the action of sub-threshold driving forces with thermal activation is known to be described by a scaling law with a certain universality class 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , which represents the mechanism of the interaction of domain walls with the applied forces over the disorder of the system. Here we show different universality classes depending on the driving forces, magnetic field or spin-polarized current, in a metallic system, which have hitherto been seen only in a magnetic semiconductor 3 , 6 . We reveal that an adiabatic spin-transfer torque plays a major role in determining the universality class of current-induced creep, which does not depend on the intricacies of material disorder. Our results shed light on the physics of the creep motion of domain walls and other elastic systems.