Ensemble inequivalence in the Blume-Emery-Griffiths model near a fourth order critical point

Abstract

The canonical phase diagram of the Blume-Emery-Griffiths (BEG) model with infinite-range interactions is known to exhibit a fourth order critical point at some negative value of the bi-quadratic interaction $K<0$. Here we study the microcanonical phase diagram of this model for $K<0$, extending previous studies which were restricted to positive $K$. A fourth order critical point is found to exist at coupling parameters which are different from those of the canonical ensemble. The microcanonical phase diagram of the model close to the fourth order critical point is studied in detail revealing some distinct features from the canonical counterpart.

9 pages, 10 figures

References in corpus (5)

• Statistical mechanics and dynamics of solvable models with long-range interactions
• Complete analysis of ensemble inequivalence in the Blume-Emery-Griffiths model
• Tricritical Behavior in Charge-Order System
• Physical interpretation of the canonical ensemble for long-range interacting systems in the absence of ensemble equivalence
• Ensemble Inequivalence and Maxwell Construction in the Self-Gravitating Ring Model

Cited by in corpus (3)

• Phase diagram of the repulsive Blume-Emery-Griffiths model in the presence of external magnetic field on a complete graph
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• Binary lattice-gases of particles with soft exclusion: Exact phase diagrams for tree-like lattices