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Energy fluctuations at the multicritical point in two-dimensional spin glasses

Hidetoshi Nishimori·Cyril Falvo·Yukiyasu Ozeki
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Abstract

We study the two-dimensional +/-J Ising model, three-state Potts model and four-state Potts model, by the numerical transfer matrix method to investigate the behaviour of the sample-to-sample fluctuations of the internal energy on the Nishimori line. The result shows a maximum at the multicritical point in all the models we investigated. The large sample-to-sample fluctuations of the internal energy as well as the existence of a singularity in these fluctuations imply that the bond configuration (or, equivalently, the distribution of frustrated plaquettes) may be experiencing a non-trivial change of its behaviour at the multicritical point. This observation is consistent with the picture that the phase transition at the multicritical point is of geometry-induced nature.

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Hidetoshi Nishimori, Cyril Falvo, Yukiyasu Ozeki. 2002-09-25. Energy fluctuations at the multicritical point in two-dimensional spin glasses. https://doi.org/10.1088/0305-4470%2F35%2F39%2F303

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