Exact Haldane mapping for all $S$ and super universality in spin chains

A. M. M. Pruisken, R. Shankar, N. Surendran

The low energy dynamics of the anti-ferromagnetic Heisenberg spin $S$ chain in the semiclassical limit $S\to \infty$ is known to map onto the O(3) nonlinear $\sigma$ model with a $\theta$ ter…