The bimodal Ising spin glass in dimension two : the anomalous dimension $\eta$

Abstract

Direct measurements of the spin glass correlation function $G(R)$ for Gaussian and bimodal Ising spin glasses in dimension two have been carried out in the temperature region $T\sim 1$. In the Gaussian case the data are consistent with the known anomalous dimension value $\eta \equiv 0$. For the bimodal spin glass in this temperature region $T>T^{\ast }(L)$, well above the crossover $T^{\ast }(L)$ to the ground state dominated regime, the effective exponent $\eta$ is clearly non-zero and the data are consistent with the estimate $\eta \sim 0.28(4)$ given by McMillan in 1983 from similar measurements. Measurements of the temperature dependence of the Binder cumulant $U_4(T,L)$ and the normalized correlation length $\xi (T,L)/L$ for the two models confirms the conclusion that the 2D bimodal model has a non-zero effective $\eta$ both below and above $T^{\ast }(L)$. The 2D bimodal and Gaussian interaction distribution Ising spin glasses are not in the same Universality class.

6 pages, 8 figures

References in corpus (6)

• Zero and low temperature behavior of the two-dimensional $\pm J$ Ising spin glass
• Correlation length of the two-dimensional Ising spin glass with bimodal interactions
• Effective critical behavior of the two-dimensional Ising spin glass with bimodal interactions
• Universality of the glassy transitions in the two-dimensional +- J Ising model
• The Ising Spin Glass in dimension four
• Evidence for non-universal scaling in dimension four Ising spin glasses

Cited by in corpus (2)

• Nonuniversality in random criticality
• Exact results for spin glass criticality