Multiple bound states in the quantum spin-1/2Heisenberg chain

Abstract
The Bethe method is used to analyse all the states of short chains of 8 and 12 atoms. The wavefunction of an isolated cluster of r deviations in an infinite chain is first expressed in the Bethe form. It is then possible to identify such clusters with reasonable confidence in short chains. In particular all the states that are not of class C have been classified in terms of multiple clusters.
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