English

Spin dynamics simulations of excitations and critical dynamics in RbMnF_3

Statistical Mechanics 2016-08-31 v1

Abstract

Spin-dynamics simulations have been used to investigate the dynamic behavior of RbMnF_3, treating it as a classical Heisenberg antiferromagnet on a simple cubic lattice. Time-evolutions of spin configurations were determined numerically from coupled equations of motion for individual spins using a new algorithm which is based on Suzuki-Trotter decompositions of exponential operators. The dynamic structure factor was calculated from the space- and time-displaced spin-spin correlation function. The crossover from hydrodynamic to critical behavior of the dispersion curve and spin-wave half-width was studied as the temperature was increased towards the critical value. The dynamic critical exponent was estimated to be z=(1.43\pm 0.03), which is slightly lower than the dynamic scaling prediction, but in good agreement with a recent experimental value. Comparisons are made of both the dispersion curve and the lineshapes obtained from our simulations with very recent experimental results for RbMnF_3 are presented.

Keywords

Cite

@article{arxiv.cond-mat/9912374,
  title  = {Spin dynamics simulations of excitations and critical dynamics in RbMnF_3},
  author = {D. P. Landau and Shan-Ho Tsai and Alex Bunker},
  journal= {arXiv preprint arXiv:cond-mat/9912374},
  year   = {2016}
}

Comments

J. Phys. Soc. Japan (in press)