English

The zero-temperature random-field Ising model on a bi-layered Bethe lattice

Statistical Mechanics 2013-08-21 v1

Abstract

The zero-temperature random-field Ising model is solved analytically for magnetisation vs external field for a bi-layered Bethe lattice. The mechanisms of infinite avalanches which are observed for small values of disorder are established. The effects of variable inter-layer interaction strengths on infinite avalanches are investigated. The spin-field correlation length is calculated and its critical behaviour is discussed. Direct Monte-Carlo simulations of spin-flip dynamics are shown to support the analytical findings. We find, paradoxically, that a reduction of the inter-layer bond strength can cause a phase transition from a regime with continuous magnetisation reversal to a regime where magnetisation exhibits a discontinuity associated with an infinite avalanche. This effect is understood in terms of the proposed mechanisms for the infinite avalanche.

Keywords

Cite

@article{arxiv.1305.5450,
  title  = {The zero-temperature random-field Ising model on a bi-layered Bethe lattice},
  author = {Thomas P Handford and Francisco J Pérez-Reche and Sergei N Taraskin},
  journal= {arXiv preprint arXiv:1305.5450},
  year   = {2013}
}

Comments

14 pages, 12 figures