Nested Bethe Ansatz for Spin Ladder Model with Open Boundary Conditions

Abstract

The nested Bethe ansatz (BA) method is applied to find theeigenvalues and the eigenvectors of the transfer matrix forspin-ladder model with open boundary conditions. Based on thereflection equation, we find the general diagonal solution, whichdetermines the general boundary interaction in the Hamiltonian. Weintroduce the spin-ladder model with open boundary conditions. Byfinding the solution K± of the reflection equationwhich determines the nontrivial boundary terms in the Hamiltonian,we diagonalize the transfer matrix of the spin-ladder model withopen boundary conditions in the framework of nested BA.