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arXiv · 0803.0444

Multicritical Nishimori point in the phase diagram of the +- J Ising model on a square lattice

Martin Hasenbusch·Francesco Parisen Toldin·Andrea Pelissetto·Ettore Vicari
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Abstract

We investigate the critical behavior of the random-bond +- J Ising model on a square lattice at the multicritical Nishimori point in the T-p phase diagram, where T is the temperature and p is the disorder parameter (p=1 corresponds to the pure Ising model). We perform a finite-size scaling analysis of high-statistics Monte Carlo simulations along the Nishimori line defined by $2p-1={\rm Tanh}(1/T)$, along which the multicritical point lies. The multicritical Nishimori point is located at p^*=0.89081(7), T^*=0.9528(4), and the renormalization-group dimensions of the operators that control the multicritical behavior are y_1=0.655(15) and y_2 = 0.250(2); they correspond to the thermal exponent ν= 1/y_2=4.00(3) and to the crossover exponent ϕ= y_1/y_2=2.62(6).

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Martin Hasenbusch, Francesco Parisen Toldin, Andrea Pelissetto, Ettore Vicari. 2008-03-04. Multicritical Nishimori point in the phase diagram of the +- J Ising model on a square lattice. https://doi.org/10.1103/physreve.77.051115

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