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Nishimori point in the 2D +/- J random-bond Ising model

A. Honecker·M. Picco·P. Pujol
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Abstract

We study the universality class of the Nishimori point in the 2D +/- J random-bond Ising model by means of the numerical transfer-matrix method. Using the domain-wall free-energy, we locate the position of the fixed point along the Nishimori line at the critical concentration value p_c = 0.1094 +/- 0.0002 and estimate nu = 1.33 +/- 0.03. Then, we obtain the exponents for the moments of the spin-spin correlation functions as well as the value for the central charge c = 0.464 +/- 0.004. The main qualitative result is the fact that percolation is now excluded as a candidate for describing the universality class of this fixed point.

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A. Honecker, M. Picco, P. Pujol. 2001-06-19. Nishimori point in the 2D +/- J random-bond Ising model. https://doi.org/10.1103/physrevlett.87.047201

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