Superconductivity with the Meron-Cluster Algorithm

TL;DR

This paper demonstrates that the meron-cluster algorithm can simulate models with continuous symmetry breaking, specifically showing evidence of a Kosterlitz-Thouless transition to superconductivity in a 2D Hubbard model variant.

Contribution

It extends the application of the meron-cluster algorithm to models with continuous symmetry breaking, revealing new insights into 2D superconducting phase transitions.

Findings

Evidence of a Kosterlitz-Thouless transition to superconductivity

Successful simulation of a continuous symmetry breaking model using the meron-cluster algorithm

Identification of spontaneous U(1) symmetry breaking in a 2D Hubbard model variant

Abstract

The meron-cluster algorithm was previously used to extensively study the physics associated with the spontaneous breaking of a discrete symmetry. We recently discovered that a larger class of models with spontaneous breaking of continuous symmetries can also be simulated using the meron-cluster algorithm. Here we study one of these new models which belongs to the attractive Hubbard model family. In particular we study the spontaneous breaking of the U(1) fermion number symmetry in two dimensions and find clear evidence for a Kosterlitz-Thouless transition to a superconducting phase.