Ising spin variable
= Ising spin variable
{c}
{title2=$\sigma_i\in\{-1,1\}$}
= Ising spin
{c}
{synonym}
An Ising <Ising spin> variable is a classical two-state degree of freedom. Its thermal mean can lie anywhere in $[-1,1]$ even though each microscopic value is $-1$ or $1$. It should not be confused with an arbitrary quantum-spin operator. Products of neighbouring <Ising spins> supply the pair interactions of the <Ising model>, and their average defines <spin magnetization>.