Double-peak specific heat anomaly and correlations in the Bose-Hubbard model

Considering the thermodynamics of bosons in a lattice described by the Bose-Hubbard Hamiltonian, we report the occurrence of anomalous double peaks in their specific heat dependence on temperature. This feature, usually associated with a high geometrical frustration, can also be a consequence of a p...

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Bibliographic Details
Published inarXiv.org
Main Authors Rizzatti, Eduardo O, Barbosa, Marco Aurélio A, Barbosa, Marcia C
Format Paper
LanguageEnglish
Published Ithaca Cornell University Library, arXiv.org 13.10.2020
Subjects
Bosons
Heat
Parameter modification
Perturbation theory
Specific heat
Temperature dependence
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Summary:Considering the thermodynamics of bosons in a lattice described by the Bose-Hubbard Hamiltonian, we report the occurrence of anomalous double peaks in their specific heat dependence on temperature. This feature, usually associated with a high geometrical frustration, can also be a consequence of a purely energetic competition. By employing self-energy functional calculations combined with finite-temperature perturbation theory, we propose a mechanism based on ground-state degeneracies expressed as residual entropies. A general decomposition of the specific heat regarding all possible transitions between the system's eingenvalues provides an insight into the nature of each maximum. Furthermore, we address how the model parameters modify the structure of these peaks based on its spectral properties and atom-atom correlation function.
ISSN:2331-8422