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Domain-Wall Energies and Magnetization of the Two-Dimensional Random-Bond Ising Model

C. Amoruso·A. K. Hartmann
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Abstract

We study ground-state properties of the two-dimensional random-bond Ising model with couplings having a concentration $p\in[0,1]$ of antiferromagnetic and $(1-p)$ of ferromagnetic bonds. We apply an exact matching algorithm which enables us the study of systems with linear dimension $L$ up to 700. We study the behavior of the domain-wall energies and of the magnetization. We find that the paramagnet-ferromagnet transition occurs at $p_c \sim 0.103$ compared to the concentration $p_n\sim 0.109$ at the Nishimory point, which means that the phase diagram of the model exhibits a reentrance. Furthermore, we find no indications for an (intermediate) spin-glass ordering at finite temperature.

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C. Amoruso, A. K. Hartmann. 2004-01-23. Domain-Wall Energies and Magnetization of the Two-Dimensional Random-Bond Ising Model. https://doi.org/10.1103/physrevb.70.134425

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