Journal of Physics A Mathematical and General
Complete integrability for a discrete Heisenberg chain
N. Papanicolaou
Abstract
Haldane (1982) conjectured that a simple generalisation of the Heisenberg spin chain leads to a completely integrable classical system without invoking the usual continuum approximation. Complete integrability is established for the generalised discrete chain by exhibiting a Lax pair and an infinite set of non-local conservation laws. The associated inverse scattering problem is also formulated providing explicit soliton solutions.