A quantum-mechanical relaxation model

Authors

Ralph Skomski, University of Nebraska-LincolnFollow
Arti Kashyap, Indian Institute of Technology Mandi, Himachal PradeshFollow
David J. Sellmyer, University of Nebraska-LincolnFollow

Document Type

Article

Date of this Version

2012

Citation

JOURNAL OF APPLIED PHYSICS 111, 07D507 (2012); doi:10.1063/1.3679605

Comments

Copyright VC 2012 American Institute of Physics.

Abstract

The atomic origin of micromagnetic damping is investigated by developing and solving a quantum-mechanical relaxation model. A projection-operator technique is used to derive an analytical expression for the relaxation time as a function of the heat-bath and interaction parameters. The present findings are consistent with earlier research beyond the Landau-Lifshitz-Gilbert (LLG) equation and show that the underlying relaxation mechanism is very general. Zermelo’s recurrence paradox means that there is no true irreversibility in non-interacting nanoparticles, but the corresponding recurrence times are very long and can be ignored in many cases.