Two numerical strategies based on the Wang–Landau and Lee entropic sampling schemes are implemented to investigate the first-order transition features of the 3D bimodal (± h) random-field Ising model at the strong disorder regime. We consider simple cubic lattices with linear sizes in the range L = 4–32 and simulate the system for two values of the disorder strength: h = 2 and 2.25. The nature of the transition is elucidated by applying the Lee–Kosterlitz free-energy barrier method. Our results indicate that, despite the strong first-order-like characteristics, the transition remains continuous, in disagreement with the early mean-field theory prediction of a tricritical point at high values of the random field.
|Journal||Journal of Statistical Mechanics: Theory and Experiment|
|Publication status||Published - 28 Mar 2008|
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Fytas, N. G., Malakis, A., & Eftaxias, K. (2008). First-order transition features of the 3D bimodal random-field Ising model. Journal of Statistical Mechanics: Theory and Experiment, 2008, [P03015]. https://doi.org/10.1088/1742-5468/2008/03/P03015