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

@article{Baek2010CommentO,
title={Comment on "Six-state clock model on the square lattice: Fisher zero approach with Wang-Landau sampling".},
author={S. K. Baek and Petter Minnhagen and B. Kim},
journal={Physical review. E, Statistical, nonlinear, and soft matter physics},
year={2010},
volume={81 6 Pt 1},
pages={
063101
}
}

Physical review. E, Statistical, nonlinear, and soft matter physics

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 that at the upper transition, the helicity modulus does make a discontinuous jump to zero. This gives strong evidence for a Kosterlitz-Thouless transition.