Second-Order Phase Transition in the Two-DimensionalClassical Lattice Coulomb Gas of Half-Integer Charges

Abstract

The second-order phase transition in the two-dimensional (2D) classicalCoulomb gas of half-integer charges on a square lattice is investigated byusing Monte Carlo simulations. Based on the finite-size scaling analysis,we estimate the second-order phase transitiontemperature Tc and the static critical exponentsβ and ν with a new numerical analysis method.More precise critical temperature Tc = 0.1311(2) and critical exponentsβ/ν = 0.1152(12) and ν = 0.857(15) are obtained.The estimated value of ν indicates that the charge latticemelting transition is different from the pure 2D Ising transition.