Phase Transition Of Laplacian Roughening Model On A Triangular Lattice Using Wang-Landau Monte Carlo Simulation And Fisher Zeros

Phase transition of the discrete Laplacian roughening model was investigated on a triangular lattice of various sizes by using the Wang-Landau (WL) Monte Carlo simulation and finite-size scaling analysis of partition-function zeros. The density of states was calculated using the WL method, and the internal energy and specific heat were calculated as a function of temperature. A single transition was observed at T-c = 1.855(5) with a new universality class of the correlation exponent nu = 0.70(1) and the specific heat exponent alpha = 0.60(4). The results were confirmed by the finite size scaling analysis of the first zeros for the partition function. The critical exponents satisfy the scaling relation alpha = 2 - d nu very well.