Integrable Open Chain Research Articles

Shor–Movassagh chain leads to unusual integrable model

The ground state of the Shor–Movassagh chain can be analytically described by the Motzkin paths. There is no analytical description of the excited states. The model is not solvable. We prove the integrability of the model without interacting part in this paper (free Shor–Movassagh). The Lax pair for the free Shor–Movassagh open chain is explicitly constructed. We further obtain the boundary K-matrices compatible with the integrability of the model on the open interval. Our construction provides a direct demonstration for the quantum integrability of the model, described by the Yang–Baxter algebra. Because the partial transpose of the R matrix is not invertible, the model does not have crossing unitarity and the integrable open chain cannot be constructed by the reflection equation (boundary Yang–Baxter equation).

Chain models on hecke algebra for corner type representations

We consider the integrable open chain models formulated in terms of generators of the Hecke algebra. The spectrum of Hamiltonians for the open Hecke chains of finite size with free boundary conditions is deduced for special (comer type) irreducible representations of the Hecke algebra.

Functional equations for transfer-matrix operators in open Hecke chain models

We consider integrable open chain models formulated in terms of the generators of affine Hecke algebras. We use the fusion procedure to construct the hierarchy of commutative elements, which are analogues of the commutative transfer matrices. These elements satisfy a set of functional relations generalizing functional relations for a family of transfer matrices in solvable spin chain models of the Uq(gl(n|m)) type.