O(n) matrix spin model with unusual critical behavior in the limit n-->
N Angelescu, M Bundaru, G Costache, CJ Thompson
Phys Rev Lett | Published : 1986
A generalized O(n) matrix version of the classical Heisenberg model, introduced by Fuller and Lenard as a classical limit of a quantum model, is solved exactly in one dimension. It is shown that even for a finite number of spins the model has a phase transition in the limit n'. The transition features a specific-heat jump, zero long-range order at all temperatures, and zero correlation length at the critical point. The Curie-Weiss version of the model is also discussed. © 1986 The American Physical Society.