Exact solution of the XXZ alternating spin chain with generic   non-diagonal boundaries
  The integrable XXZ alternating spin chain with generic non-diagonal boundary terms specified by the most general non-diagonal K-matrices is studied via the off-diagonal Bethe Ansatz method. Based on the intrinsic properties of the fused R-matrices and K-matrices, we obtain certain closed operator identities and conditions, which allow us to construct an inhomogeneous T-Q relation and the associated Bethe Ansatz equations accounting for the eigenvalues of the transfer matrix. 
Junpeng Cao, Wen-Li Yang, Kangjie Shi and Yupeng Wang
cond-mat.stat-mech hep-th math-ph math.MP