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

作者：Hasenbusch Martin; Toldin Francesco Parisen; Pelissetto Andrea; Vicari Ettore

来源：Physical Review E, 2008, 77(5): 051115.

DOI：10.1103/PhysRevE.77.051115

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 = tanh(1/T), along which the multicritical point lies. The multicritical Nishimori point is located at p*=0.890 81(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 nu equivalent to 1/y(2)=4.00(3) and to the crossover exponent phi equivalent to y(1)/y(2)=2.62(6).

• 出版日期2008-5
• 单位中国科学院金属研究所