First order transition in a three dimensional disordered system

L. A. Fernandez; A. Gordillo-Guerrero; V. Martin-Mayor; J. J. Ruiz-Lorenzo

doi:10.1103/physrevlett.100.057201

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arXiv · 0711.0856

First order transition in a three dimensional disordered system

L. A. Fernandez·A. Gordillo-Guerrero·V. Martin-Mayor·J. J. Ruiz-Lorenzo

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Abstract

We present the first detailed numerical study in three dimensions of a first-order phase transition that remains first-order in the presence of quenched disorder (specifically, the ferromagnetic/paramagnetic transition of the site-diluted four states Potts model). A tricritical point, which lies surprisingly near to the pure-system limit and is studied by means of Finite-Size Scaling, separates the first-order and second-order parts of the critical line. This investigation has been made possible by a new definition of the disorder average that avoids the diverging-variance probability distributions that plague the standard approach. Entropy, rather than free energy, is the basic object in this approach that exploits a recently introduced microcanonical Monte Carlo method.

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L. A. Fernandez, A. Gordillo-Guerrero, V. Martin-Mayor, J. J. Ruiz-Lorenzo. 2007-11-06. First order transition in a three dimensional disordered system. https://doi.org/10.1103/physrevlett.100.057201

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