We consider the open XXZ quantum spin chain with nondiagonal boundary terms. For bulk anisotropy value η = iπ/p+1, p = 1, 2, ..., we propose an exact (p + 1)-order functional relation for the transfer matrix, which implies Bethe-ansatz-like equations for the corresponding eigenvalues. The key observation is that the fused spin-p+1/2 transfer matrix can be expressed in terms of a lower-spin transfer matrix, resulting in the truncation of the fusion hierarchy.
ASJC Scopus subject areas
- Nuclear and High Energy Physics