Nonequivalence of ensembles for long-range quantum spin systems in optical lattices

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dc.contributor.authorKastner M.
dc.date.accessioned2011-05-15T16:05:18Z
dc.date.available2011-05-15T16:05:18Z
dc.date.issued2010
dc.description.abstractMotivated by the anisotropic long-range nature of the interactions between cold dipolar atoms or molecules in an optical lattice, we study the anisotropic quantum Heisenberg model with Curie-Weiss-type long-range interactions. Absence of a heat bath in optical lattice experiments suggests a study of this model within the microcanonical ensemble. The microcanonical entropy is calculated analytically and nonequivalence of microcanonical and canonical ensembles is found for a range of anisotropy parameters. From the shape of the entropy it follows that the Curie-Weiss Heisenberg model is indistinguishable from the Curie-Weiss Ising model in canonical thermodynamics, although their microcanonical thermodynamics differs. Qualitatively, the observed features of nonequivalent ensembles are expected to be relevant for long-range quantum spin systems realized in optical lattice experiments. © 2010 The American Physical Society.
dc.description.versionArticle
dc.identifier.citationPhysical Review Letters
dc.identifier.citation104
dc.identifier.citation24
dc.identifier.issn319007
dc.identifier.other10.1103/PhysRevLett.104.240403
dc.identifier.urihttp://hdl.handle.net/10019.1/13066
dc.subjectAnisotropy parameters
dc.subjectCanonical ensemble
dc.subjectHeat bath
dc.subjectHeisenberg models
dc.subjectLong range interactions
dc.subjectMicrocanonical ensembles
dc.subjectMicrocanonical entropy
dc.subjectMicrocanonical thermodynamics
dc.subjectOptical lattices
dc.subjectQuantum spin systems
dc.subjectAnisotropy
dc.subjectCrystal lattices
dc.subjectIsing model
dc.subjectOptical materials
dc.subjectSpin dynamics
dc.subjectThermodynamics
dc.subjectExperiments
dc.titleNonequivalence of ensembles for long-range quantum spin systems in optical lattices
dc.typeArticle
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