English

Nonlinear ac stationary response and dynamic magnetic hysteresis of quantum uniaxial superparamagnets

Mesoscale and Nanoscale Physics 2015-11-18 v2

Abstract

The nonlinear ac stationary response of uniaxial paramagnets and superparamagnets - nanoscale solids or clasters with spin number S ~ 10^0 - 10^4 - in superimposed uniform ac and dc bias magnetic fields of arbitrary strength, each applied along the easy axis of magnetization, is determined by solving the evolution equation for the reduced density matrix represented as a finite set of three-term differential-recurrence relations for its diagonal matrix elements. The various harmonic components of the magnetization, dynamic magnetic hysteresis loops, etc. are then evaluated via matrix continued fractions indicating a pronounced dependence of the nonlinear response on S arising from the quantum spin dynamics. In the linear response approximation, the results concur with existing solutions.

Keywords

Cite

@article{arxiv.1509.05616,
  title  = {Nonlinear ac stationary response and dynamic magnetic hysteresis of quantum uniaxial superparamagnets},
  author = {Yuri P. Kalmykov and Serguey V. Titov and William T. Coffey},
  journal= {arXiv preprint arXiv:1509.05616},
  year   = {2015}
}

Comments

28 pages, 10 figures, 33 refererences