Quantum rotor description of the Mott-insulator transition in the Bose-Hubbard model

Abstract

We present the novel approach to the Bose-Hubbard model using the $\mathrm{U}(1)$ quantum rotor description. The effective action formalism allows us to formulate a problem in the phase only action and obtain an analytical formulas for the critical lines. We show that the nontrivial $\mathrm{U}(1)$ phase field configurations have an impact on the phase diagrams. The topological character of the quantum field is governed by terms of the integer charges - winding numbers. The comparison presented results to recently obtained quantum Monte Carlo numerical calculations suggests that the competition between quantum effects in strongly interacting boson systems is correctly captured by our model.

accepted to PRB

References in corpus (3)

• Generalized Directed Loop Method for Quantum Monte Carlo Simulations
• Mott insulator to superfluid transition in the Bose-Hubbard model: a strong-coupling approach
• The Mott insulator phase of the one dimensional Bose-Hubbard model: a high order perturbative study

Cited by in corpus (4)

• Lieb-Robinson Bounds for Harmonic and Anharmonic Lattice Systems
• Superfluid to Mott-insulator transition of hardcore bosons in a superlattice
• Mott transition in bosonic systems: Insights from the variational approach
• Superfluid to Mott-insulator transition in an anizotropic two--dimensional optical lattice