Interface entropy and phase transitions in frustrated ising systems

Abstract

It is pointed out that the vanishing of the interface energy at T = 0 is compatible with the existence of a phase transition at finite temperature in Ising systems. In frustrated systems an interface may cost entropy. This effect may be sufficient to produce a non-zero transition temperature. We give an explicit example of this behaviour on a periodic model. Some possible consequences for 2-D Ising spin-glasses are discussed