Anisotropic surface tension, step free energy, and interfacial roughening in the three-dimensional Ising model.

Abstract

The anisotropic interfacial tension of a simple-cubic Ising model is calculated for the first time by use of extensive Monte Carlo studies with a tilted interface for a wide range of lattice size L and temperature T. The size dependence of the step free energy is used to probe the correlation length near the roughening transition and confirms the expected square-root T dependence. Finite-size scaling implies that the step free energy varies as 1/L in the rough phase, and thus the applicability of a capillary-wave Hamiltonian to describe interfaces of lattice models may be limited.