Off-diagonal Bethe Ansatz on the so(5) spin chain

Abstract

The so(5) (i.e., B2) quantum integrable spin chains with both periodic and non-diagonal boundaries are studied via the off-diagonal Bethe Ansatz method. By using the fusion technique, sufficient operator product identities (comparing to those in [1]) to determine the spectrum of the transfer matrices are derived. For the periodic case, we recover the results obtained in [1], while for the non-diagonal boundary case, a new inhomogeneous T−Q relation is constructed. The present method can be directly generalized to deal with the so(2n+1) (i.e., Bn) quantum integrable spin chains with general boundaries.