with

External Sources and Boundaries

We will consider here the technical question of how to implement the Wolff cluster algorithm for the Ising model in the presence of arbitrary external sources. We will also consider the use of the algorithm in lattices with fixed rather than periodical boundary conditions, as well as the use of truncated clusters. We will not deal with the technical aspects relating to how well the algorithm itself works, with respect to the elimination of the phenomenon of critical slowing down. For that, the reader is referred to the original papers on the cluster algorithms [1,2].

- The Wolff Algorithm
- Arbitrary External Sources
- Fixed Boundary Conditions
- Superclusters and Truncated Clusters
- Optimization of the Algorithm
- Fortran Routines
- Bibliography