Effective critical behavior of the two-dimensional Ising spin glass with bimodal interactions

TL;DR

This study uses Monte Carlo simulations to analyze the low-temperature behavior of the 2D Ising spin glass with bimodal interactions, questioning whether it shares universality with the Gaussian-distributed model.

Contribution

It provides new Monte Carlo data and analysis challenging the claim that bimodal and Gaussian 2D Ising spin glasses share the same universality class at low temperatures.

Findings

Results do not conclusively support shared universality class

Finite-size effects limit definitive conclusions

Data suggest differences in critical behavior at low temperatures

Abstract

Monte Carlo data of the two-dimensional Ising spin glass with bimodal interactions are presented with the aim of understanding the low-temperature physics of the model. An analysis of the specific heat, spin-glass susceptibility, finite-size correlation length, and the Binder ratio is performed to try to verify a recent proposal in which for large system sizes and finite but low temperatures the effective critical exponents are identical to the critical exponents of the two-dimensional Ising spin glass with Gaussian interactions. Our results show that with present system sizes the recently proposed scenario in which the two-dimensional Ising spin glass with bimodally distributed interactions is in the same universality class as the model with Gaussian-distributed disorder at low but finite temperatures cannot be reliably proven.