Restoring isotropy in a three-dimensional lattice model: The Ising universality class

Understand

We study a generalized Blume-Capel model on the simple cubic lattice.

• In addition to the nearest neighbor coupling there is a next to next to nearest neighbor coupling.
• In order to quantify spatial anisotropy, we determine the correlation length in the high temperature phase of the model for three different directions.
• It turns out that the spatial anisotropy depends very little on the dilution parameter $D$ of the model and is essentially determined by the ratio of the nearest neighbor and the next to next to nearest neighbor coupling.