Phys.org May 10, 2023
Magnetic frustrations and dimensionality play an important role in determining the nature of the magnetic long-range order and how it melts at temperatures above the ordering transition TN. A team of researchers in the US (Rice University, Ames National Laboratory, Iowa State University) used large-scale Monte Carlo simulations to study these phenomena in a class of frustrated Ising spin models in two spatial dimensions. They found that the melting of the magnetic long-range order into an isotropic gas like paramagnet proceeded via an intermediate stage where the classical spins remained anisotropically correlated. The correlated paramagnet existed in a temperature range TN<T<T∗, whose width increased as magnetic frustrations grew. This intermediate phase was typically characterized by short-range correlations; however, the two-dimensional nature of the model allowed for an additional exotic feature—formation of an incommensurate liquidlike phase with algebraically decaying spin correlations. According to the researchers the two-stage melting of magnetic order is generic and pertinent to many frustrated quasi-2D magnets with large (essentially classical) spins… read more. TECHNICAL ARTICLE
Schematic diagram (a) demonstrating the concept of anisotropic melting in a 2D Ising system… Credit: Phys. Rev. Lett. 130, 166701, 19 April2023