Critical Behavior of the Three-Dimensional ±J Model in a Magnetic Field

抄録

The three-dimensional ±J Ising spin glass model is investigated by means of Monte Carlo simulation. In uniform fields of various strength, the Edwards-Anderson susceptibility χ_EAQ is calculated at T=0.9J which is lower than the transition temperature in the zero-field case. It is found that χ_EA decreases monotonically when the field strength is increased and that the data do not suggest a phase transition in a finite field. The best parameters for the scaling function of the form χ_EA(H)\simeql^ψ\ ildeχ_EA((H−H_c)l^−φ) are estimated to be H_c=0.00(10)J, ψ=2.16(22) and φ=−1.13(6). These results support the hypothesis that the phase transition does not exist in a finite magnetic field.