The XY model is an O(2) model of spin statistics.
In d = 2 dimensions, the XY model exhibits an infinite-order topological phase change: the Kosterlitz–Thouless transition.
This program simulates the XY model on a 2-dimensional lattice with periodic boundary conditions, which undergoes the Kosterlitz–Thouless transition at β ≈ 0.5.
Clone and make && make clean.
./xy. Run with --usage or --help for help. It takes arguments for most parameters and will run with sane defaults if none are given.
![[〈|_M_|^2〉 against _β_ for 10000 and 100000 iterations]](https://rawgithub.com/iamfionn/xy/master/graph/graph.svg)