English

Evidence for power-law Griffiths singularities in a layered Heisenberg magnet

Strongly Correlated Electrons 2012-09-10 v1 Disordered Systems and Neural Networks Statistical Mechanics

Abstract

We study the ferromagnetic phase transition in a randomly layered Heisenberg model. A recent strong-disorder renormalization group approach [Phys. Rev. B 81, 144407 (2010)] predicted that the critical point in this system is of exotic infinite-randomness type and is accompanied by strong power-law Griffiths singularities. Here, we report results of Monte-Carlo simulations that provide numerical evidence in support of these predictions. Specifically, we investigate the finite-size scaling behavior of the magnetic susceptibility which is characterized by a non-universal power-law divergence in the Griffiths phase. In addition, we calculate the time autocorrelation function of the spins. It features a very slow decay in the Griffiths phase, following a non-universal power law in time.

Keywords

Cite

@article{arxiv.1005.5484,
  title  = {Evidence for power-law Griffiths singularities in a layered Heisenberg magnet},
  author = {Fawaz Hrahsheh and Hatem Barghathi and Priyanka Mohan and Rajesh Narayanan and Thomas Vojta},
  journal= {arXiv preprint arXiv:1005.5484},
  year   = {2012}
}

Comments

4 pages, 3 eps figures, submitted to the proceedings of SCES 2010