It has been observed that in the isotropic spin-1 chain a transition in the asymptotic properties of the correlation function (commensurate-incommensurate transition) occurs at the AKLT point. We propose a simple random-walk-type argument, explaining this transition. Also, we consider a modification of the AKLT model, for which this argument can be turned into a rigorous proof.
- AKLT model
- Commensurate-incommensurate transition
- Isotropic spin-1 chain