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arXiv · 1107.1314

Quantum criticality of a Bose gas in an optical lattice near the Mott transition

A. Rancon·N. Dupuis
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Abstract

We derive the equation of state of bosons in an optical lattice in the framework of the Bose-Hubbard model. Near the density-driven Mott transition, the expression of the pressure P(μ,T) versus chemical potential and temperature is similar to that of a dilute Bose gas but with renormalized mass m^* and scattering length a^*. m^* is the mass of the elementary excitations at the quantum critical point governing the transition from the superfluid phase to the Mott insulating phase, while a^* is related to their effective interaction at low energy. We use a nonperturbative renormalization-group approach to compute these parameters as a function of the ratio t/U between hopping amplitude and on-site repulsion.

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A. Rancon, N. Dupuis. 2011-10-19. Quantum criticality of a Bose gas in an optical lattice near the Mott transition. https://doi.org/10.1103/physreva.85.011602

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