In statistical physics, the classical Heisenberg model, developed by Werner Heisenberg, is the
The classical Heisenberg model can be formulated as follows: take a d-dimensional lattice, and place a set of spins of unit length, on each lattice node.
The model is defined through the following Hamiltonian: where is a coupling between spins.
Independently of the range of the interaction, at a low enough temperature the magnetization is positive.
Conjecturally, in each of the low temperature extremal states the truncated correlations decay algebraically.