Bethe ansatz solution of the $\tau_2$-model with arbitrary boundary   fields
  The quantum $\tau_2$-model with generic site-dependent inhomogeneity and arbitrary boundary fields is studied via the off-diagonal Bethe Ansatz method. The eigenvalues of the corresponding transfer matrix are given in terms of an inhomogeneous T-Q relation, which is based on the operator product identities among the fused transfer matrices and the asymptotic behavior of the transfer matrices. Moreover, the associated Bethe Ansatz equations are also obtained. 
Xiaotian Xu, Kun Hao, Tao Yang, Junpeng Cao, Wen-Li Yang and Kangjie   Shi
math-ph cond-mat.stat-mech hep-th math.MP