Comment on `Six-state clock model on the square lattice: Fisher zero approach with Wang-Landau sampling'

TL;DR

This paper provides simulation evidence that the upper transition in the six-state clock model on a square lattice is of the Kosterlitz-Thouless type, contrary to previous suggestions that it was not.

Contribution

The study offers new simulation results demonstrating the Kosterlitz-Thouless nature of the upper transition in the six-state clock model, challenging prior claims.

Findings

Helicity modulus jumps to zero at the upper transition

Evidence supports the Kosterlitz-Thouless transition nature

Contradicts previous claims about the transition type

Abstract

Hwang in [Phys. Rev. E 80, 042103 (2009)] suggested that the two transitions of the six-state clock model on the square lattice are not of the Kosterlitz-Thouless type. Here we show from simulations thatat the upper transition, the helicity modulus does make a discontinuous jump to zero. This gives strong evidence for a Kosterlitz-Thouless transition.