# Extended gaussian ensemble solution and tricritical points of a system with long-range interactions - Condensed Matter > Statistical Mechanics

Extended gaussian ensemble solution and tricritical points of a system with long-range interactions - Condensed Matter > Statistical Mechanics - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Abstract: The gaussian ensemble and its extended version theoretically play theimportant role of interpolating ensembles between the microcanonical and thecanonical ensembles. Here, the thermodynamic properties yielded by the extendedgaussian ensemble EGE for the Blume-Capel BC model with infinite-rangeinteractions are analyzed. This model presents different predictions for thefirst-order phase transition line according to the microcanonical and canonicalensembles. From the EGE approach, we explicitly work out the analyticalmicrocanonical solution. Moreover, the general EGE solution allows one toillustrate in details how the stable microcanonical states are continuouslyrecovered as the gaussian parameter $\gamma$ is increased. We found out that itis not necessary to take the theoretically expected limit $\gamma \to \infty$to recover the microcanonical states in the region between the canonical andmicrocanonical tricritical points of the phase diagram. By analyzing theentropy as a function of the magnetization we realize the existence ofunaccessible magnetic states as the energy is lowered, leading to a treaking ofergodicity.

Autor: Rafael B. Frigori, Leandro G. Rizzi, Nelson A. Alves

Fuente: https://arxiv.org/