Spin Glass Server
(This service is provided by COPhy and
M. Jünger's group.)
This page offers a service to compute exact ground states of
Ising spin glasses
Instances can be uploaded using this web-interface or our
(for Unix/Linux based OS).
The results are returned by email.
We recommend to use the command-line client for the submission of many instances.
The following geometries are supported:
- Ising spin glass on a:
- two-dimensional planar quadratic lattice (free boundary in at least one direction)
- two-dimensional quadratic lattice on a torus (periodic boundaries in both directions)
- three-dimensional lattice (periodic boundaries in all directions)
- complete graph (Sherrington-Kirkpatrick (SK) spin-glass model)
For the SK model, we use an algorithm
provided to us by our colleagues G. Rinaldi, F. Rendl and A. Wiegele.
Submit your file(s) ...
(each instance has to be a text file; files can be bundled into an archive; supported archive-formats are tar, tar.gz and zip)
The input format is as follows:
name: the name of the instance
spin_i1 spin_j1 coupling between i1 and j1
spin_i2 spin_j2 coupling between i2 and j2
If the instance should be named like the filename, simply skip the line
in the file.
Lattices with uniformly distributed ±J couplings need to be scaled to ±1 couplings.
See an example of the input format together with the corresponding results from the server here
For lattice models, spins are numbered sequentially layer by layer starting with index 1.
For example, a two-dimensional 3x3 spin glass is numbered as follows:
For the non-lattice models such as the Sherrington-Kirkpatrick (SK) model, the order of the spins is arbitrary.
If you have any special request or problems, please contact us directly: spinglass AT informatik.uni-koeln.de
A more general instance generator can be downloaded