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.
F. Hrahsheh et al., "Evidence for Power-Law Griffiths Singularities in a Layered Heisenberg Magnet," Journal of Physics: Conference Series, vol. 273, no. 1, Institute of Physics - IOP Publishing, Jun 2011.
The definitive version is available at http://dx.doi.org/10.1088/1742-6596/273/1/012004
International Conference on Strongly Correlated Electron Systems (2010: Jun. 27-Jul. 2, Santa Fe, NM)
Keywords and Phrases
Critical points; Ferromagnetic Phase Transition; Finite-size scaling behavior; Griffiths phase; Griffiths singularities; Heisenberg magnet; Heisenberg models; Monte Carlo Simulation; Numerical evidence; Power law divergence; Power-law; Renormalization group approach; Time autocorrelation functions; Magnetic susceptibility; Statistical mechanics; Regression analysis
International Standard Serial Number (ISSN)
Article - Conference proceedings
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