‘Bethe-ansatz-free’ eigenstates for spin-1/2 Richardson–Gaudin integrable models

Bethe Ansatz works for integrable model

Thermodynamic Bethe ansatz equation for osp(1|2) integrable spin chain

The thermodynamic Bethe ansatz is applied to a quantum integrable spin chain associated with the Lie superalgebra osp(1|2). Using the string hypothesis, we derive a set of infinite number of non-linear integral equations (thermodynamic Bethe ansatz equation), which characterize the free energy. The low temperature limit of the free energy is also discussed. Modern Physics Letters A, in press. S...

On quantum group symmetry and Bethe ansatz for the asymmetric twin spin chain with integrable boundary

Motivated by a study of the crossing symmetry of the asymmetric twin or ‘gemini’ representation of the affine Hecke algebra we give a construction for crossing tensor space representations of ordinary Hecke algebras. These representations build solutions to the Yang– Baxter equation satisfying the crossing condition (that is, integrable quantum spin chains). We show that every crossing represen...

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

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. ...

Thermodynamic Bethe ansatz equation from fusion hierarchy of osp(1|2) integrable spin chain

The thermodynamic Bethe ansatz (TBA) and the excited state TBA equations for an integrable spin chain related to the Lie superalgebra osp(1|2) are proposed by the quantum transfer matrix (QTM) method. We introduce the fusion hierarchy of the QTM and derive the functional relations among them (T -system) and their certain combinations (Y -system). Their analytical property leads to the non-linea...