Complete Bethe Ansatz solution of the open spin-s XXZ chain with general integrable boundary terms

Luc Frappat (1) , Rafael Nepomechie (2) , Eric Ragoucy (1)

1 LAPTH - Laboratoire d'Annecy-le-Vieux de Physique Théorique
2 Physics Department

We consider the open spin-s XXZ quantum spin chain with N sites and general integrable boundary terms for generic values of the bulk anisotropy parameter, and for values of the boundary parameters which satisfy a certain constraint. We derive two sets of Bethe Ansatz equations, and find numerical evidence that together they give the complete set of $(2s+1)^{N}$ eigenvalues of the transfer matrix. For the case s=1, we explicitly determine the Hamiltonian, and find an expression for its eigenvalues in terms of Bethe roots.

Domaines: Physique mathématique [math-ph]; Physique mathématique [math-ph]; Physique des Hautes Energies - Théorie [hep-th]

Luc Frappat, Rafael Nepomechie, Eric Ragoucy. Complete Bethe Ansatz solution of the open spin-s XXZ chain with general integrable boundary terms. 2007. ⟨hal-00160040v1⟩