Microcanonical phase diagrams of short-range ferromagnets

Abstract

A phase diagram is a graph in parameter space showing the phase boundaries of a many-particle system. Commonly, the control parameters are chosen to be those of the (generalized) canonical ensemble, such as temperature and magnetic field. However, depending on the physical situation of interest, the (generalized) microcanonical ensemble may be more appropriate, with the corresponding control parameters being energy and magnetization. We show that the phase diagram on this parameter space looks remarkably different from the canonical one. The general features of such a microcanonical phase diagram are investigated by studying two models of ferromagnets with short-range interactions. The physical consequences of the findings are discussed, including possible applications to nuclear fragmentation, adatoms on surfaces, and cold atoms in optical lattices.

5 pages, 3 figures

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Cited by in corpus (14)

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• Canonical free-energy barrier of particle and polymer cluster formation
• Phase transitions at high energy vindicate negative microcanonical temperature
• Nonequivalence of ensembles in the Curie-Weiss anisotropic quantum Heisenberg model
• Ising metamagnets in thin film geometry: equilibrium properties
• Exploring different regimes in finite-size scaling of the droplet condensation-evaporation transition
• First-order phase transitions from poles in asymptotic representations of partition functions
• On the thermodynamics of classical micro-canonical systems
• Dynamical and statistical bimodality in nuclear fragmentation
• Squeezed ensemble for systems with first-order phase transitions
• Finite size effects on the phase diagram of the thermodynamical cluster model
• Microcanonical entropy of the spherical model with nearest-neighbour interactions
• Microcanonical analysis of the Curie-Weiss anisotropic quantum Heisenberg model in a magnetic field
• Phenomenological theory of the Potts model evaporation-condensation transition