Hi Michal Maik,

Winding numbers only exist for lattices with periodic boundary conditions - otherwise world lines cannot wind.

Matthias Troyer

On Apr 13, 2010, at 12:29 AM, Michał Maik wrote:

Hi,

I am having a problem calculating the "Winding Number vs Energy" graph for certain models. When I do it for the "4-site mixed" I am not able to get it to work but if I use a "square lattice" with L=2 it seems to work fine. I am wondering how I have to define a model in order to calculate the winding numbers.

Regards

Michal Maik