Non-Gibbs states on a Bose-Hubbard Lattice
ORAL
Abstract
We study the equilibrium properties of the repulsive quantum Bose-Hubbard model at high temperatures in arbitrary dimensions, with and without disorder. In its microcanonical setting the model conserves energy and particle number. The microcanonical dynamics is characterized by a pair of two densities: energy density ε and particle number density n. The macrocanonical Gibbs distribution also depends on two parameters: the inverse nonnegative temperature β and the chemical potential μ. We prove the existence of non-Gibbs states, that is, pairs (ε,n) which can not be mapped onto (β,μ). The separation line in the density control parameter space between Gibbs and non-Gibbs states ε∼n2 corresponds to infinite temperature β=0. The non-Gibbs phase can not be cured into a Gibbs one within the standard Gibbs formalism using negative temperatures.
*This work was supported by the Institute for Basic Science, Project Code IBS-R024-D1. TE acknowledges financial support by the Alexander-von-Humboldt foundation through the Feodor-Lynen Research Fellowship program Nr. NZL-1007394-FLF-P.
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Presenters
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Sergej Flach
- Center for Theoretical Phypsics of Complex Systems, Institute for Basic Science
- Center for Theoretical Physics of Complex Systems, Institute for Basic Science
- Center for Theoretical Physics of Complex Systems, Institute for Basic Science, Daejeon 34051, Korea
- Center for Theoretical Physics for Complex Systems, Institute for Basic Science