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

Journal Article · Sat Sep 01 00:00:00 EDT 2007 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.76.094503· OSTI ID:21055184

Polak, T P; Kopec, T K ^[1]

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1. Institute for Low Temperatures and Structure Research, Polish Academy of Sciences, P.O. Box 1410, 50-950 Wroclaw 2 (Poland)

We present an approach to the Bose-Hubbard model using the U(1) quantum rotor description. The effective action formalism allows us to formulate a problem in the phase only action and obtain analytical formulas for the critical lines. We show that the nontrivial 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 of 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.

• OSTI ID: 21055184
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Vol. 76, Issue 9; Other Information: DOI: 10.1103/PhysRevB.76.094503; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ACTION INTEGRAL
BOSONS
COMPARATIVE EVALUATIONS
CONFIGURATION
HUBBARD MODEL
INTERACTING BOSON MODEL
METALS
MONTE CARLO METHOD
PHASE DIAGRAMS
ROTORS
TOPOLOGY