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arXiv · 1012.0166

Non-perturbative renormalization-group approach to the Bose-Hubbard model

A. Rancon·N. Dupuis
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Abstract

We present a non-perturbative renormalization-group approach to the Bose-Hubbard model. By taking as initial condition of the RG flow the (local) limit of decoupled sites, we take into account both local and long-distance fluctuations in a nontrivial way. This approach yields a phase diagram in very good quantitative agreement with the quantum Monte Carlo results and reproduces the two universality classes of the superfluid--Mott-insulator transition with a good estimate of the critical exponents. Furthermore, it reveals the crucial role of the "Ginzburg length" as a crossover length between a weakly- and a strongly-correlated superfluid phase.

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A. Rancon, N. Dupuis. 2011-06-02. Non-perturbative renormalization-group approach to the Bose-Hubbard model. https://doi.org/10.1103/physrevb.83.172501

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