Title

Mean field theory of the general-spin Ising model

Abstract

In psychology, the Ising model is often used to model pathologies like depression, where symptoms are represented as nodes and their associations as links. However, a limitation of the traditional Ising model is its binary nature, which fails to capture more subtle variations in states. The general-spin Ising model extends this by allowing 2k + 1 spin values: −1, −(k+1)/k, …, 0, 1/k, …, 1. In this talk, we derive the mean field of the general-spin Ising model using the variational principle of Gibbs free energy. Like the standard Ising model, it exhibits spontaneous magnetization, but with a shift depending on the number of categories. Additionally, the hysteresis effect decreases as the number of spin categories increases. Monte Carlo simulations confirm our theoretical results.

If you wish to attend this seminar online, please send an email to f.a.nobregasantos@uva.nl to receive the zoom-link.