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arXiv · 0704.0396

Finite-temperature phase transitions in a two-dimensional boson Hubbard model

Min-Chul Cha·Ji-Woo Lee
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Abstract

We study finite-temperature phase transitions in a two-dimensional boson Hubbard model with zero-point quantum fluctuations via Monte Carlo simulations of quantum rotor model, and construct the corresponding phase diagram. Compressibility shows a thermally activated gapped behavior in the insulating regime. Finite-size scaling of the superfluid stiffness clearly shows the nature of the Kosterlitz-Thouless transition. The transition temperature, $T_c$, confirms a scaling relation $T_c \propto ρ_0^x$ with $x=1.0$. Some evidences of anomalous quantum behavior at low temperatures are presented.

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Min-Chul Cha, Ji-Woo Lee. 2007-04-03. Finite-temperature phase transitions in a two-dimensional boson Hubbard model. https://doi.org/10.1103/physrevlett.98.266406

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