paper

Random Transverse Field Ising Model in dimension : Infinite Disorder scaling via a non-linear transfer approach

arXiv:1111.3468 · doi:10.1088/1742-5468/2012/01/P01008

Abstract

The 'Cavity-Mean-Field' approximation developed for the Random Transverse Field Ising Model on the Cayley tree [L. Ioffe and M. Mézard, PRL 105, 037001 (2010)] has been found to reproduce the known exact result for the surface magnetization in [O. Dimitrova and M. Mézard, J. Stat. Mech. (2011) P01020]. In the present paper, we propose to extend these ideas in finite dimensions via a non-linear transfer approach for the surface magnetization. In the disordered phase, the linearization of the transfer equations correspond to the transfer matrix for a Directed Polymer in a random medium of transverse dimension , in agreement with the leading order perturbative scaling analysis [C. Monthus and T. Garel, arxiv:1110.3145]. We present numerical results of the non-linear transfer approach in dimensions and . In both cases, we find that the critical point is governed by Infinite Disorder scaling. In particular exactly at criticality, the one-point surface magnetization scales as , where coincides with the droplet exponent of the corresponding Directed Polymer model, with and . The distribution of the positive random variable of order O(1) presents a power-law singularity near the origin with so that all moments of the surface magnetization are governed by the same power-law decay with independently of the order .

v2=revised version (12 pages, 15 figures)

References in corpus (5)

Cited by in corpus (9)