0000000000614515

AUTHOR

L. De Cesare

showing 3 related works from this author

Thermodynamic properties of a classical d-dimensional spin-S Heisenberg ferromagnet with long-range interactions via the spectral density method

2003

The thermodynamic properties of a classical d-dimensional spin-S Heisenberg ferromagnet, with long-range interactions decaying as $r^{-p}$ and in the presence of an external magnetic field, is investigated by means of the spectral density method in the framework of classical statistical mechanics. We find that long-range order exists at finite temperature for $dd$ with $d>2$, consistently with known theorems. Besides, the related critical temperature is determined and a study of the critical properties is performed.

Statistics and ProbabilityPhysicsCondensed matter physicsStatistical Mechanics (cond-mat.stat-mech)Heisenberg modelOrder (ring theory)Spectral densityFOS: Physical sciencesStatistical mechanicsClassical Heisenberg modelCondensed Matter PhysicsMagnetic fieldFerromagnetismQuantum mechanicsCondensed Matter - Statistical MechanicsSpin-½
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Thermodynamics of the Classical Planar Ferromagnet Close to the Zero-Temperature Critical Point: A Many-Body Approach

2012

We explore the low-temperature thermodynamic properties and crossovers of ad-dimensional classical planar Heisenberg ferromagnet in a longitudinal magnetic field close to its field-induced zero-temperature critical point by employing the two-time Green’s function formalism in classical statistical mechanics. By means of a classical Callen-like method for the magnetization and the Tyablikov-like decoupling procedure, we obtain, for anyd, a low-temperature critical scenario which is quite similar to the one found for the quantum counterpart. Remarkably, ford>2the discrimination between the two cases is found to be related to the different values of the shift exponent which governs the beha…

Computer Science::Machine LearningPhysicsArticle SubjectCondensed matter physicsThermodynamicsStatistical mechanicsCondensed Matter PhysicsComputer Science::Digital Librarieslcsh:QC1-999Statistics::Machine LearningReduced propertiesCritical point (thermodynamics)Critical lineComputer Science::Mathematical SoftwareExponentCritical exponentQuantumlcsh:PhysicsPhase diagramAdvances in Condensed Matter Physics
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The Classical Spectral Density Method at Work: The Heisenberg Ferromagnet

2006

In this article we review a less known unperturbative and powerful many-body method in the framework of classical statistical mechanics and then we show how it works by means of explicit calculations for a nontrivial classical model. The formalism of two-time Green functions in classical statistical mechanics is presented in a form parallel to the well known quantum counterpart, focusing on the spectral properties which involve the important concept of spectral density. Furthermore, the general ingredients of the classical spectral density method (CSDM) are presented with insights for systematic nonperturbative approximations to study conveniently the macroscopic properties of a wide variet…

Statistical Mechanics (cond-mat.stat-mech)FOS: Physical sciencesCondensed Matter - Statistical Mechanics
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