English

Finite-Temperature Phase Diagram of Hard-Core Bosons in Two Dimensions

Superconductivity 2009-11-07 v2 Statistical Mechanics

Abstract

We determine the finite-temperature phase diagram of the square lattice hard-core boson Hubbard model with nearest neighbor repulsion using quantum Monte Carlo simulations. This model is equivalent to an anisotropic spin-1/2 XXZ model in a magnetic field. We present the rich phase diagram with a first order transition between solid and superfluid phase, instead of a previously conjectured supersolid and a tricritical end point to phase separation. Unusual reentrant behavior with ordering upon increasing the temperature is found, similar to the Pomeranchuk effect in 3He.

Keywords

Cite

@article{arxiv.cond-mat/0110024,
  title  = {Finite-Temperature Phase Diagram of Hard-Core Bosons in Two Dimensions},
  author = {Guido Schmid and Synge Todo and Matthias Troyer and Ansgar Dorneich},
  journal= {arXiv preprint arXiv:cond-mat/0110024},
  year   = {2009}
}

Comments

4 pages, 4 figures