Thermal Bethe-Ansatz Method for the Spin-1/2 XXZ Heisenberg Chain

Functional relations and Bethe Ansatz for the XXZ chain

There is an approach due to Bazhanov and Reshetikhin for solving integrable RSOS models which consists of solving the functional relations which result from the truncation of the fusion hierarchy. We demonstrate that this is also an effective means of solving integrable vertex models. Indeed, we use this method to recover the known Bethe Ansatz solutions of both the closed and open XXZ quantum ...

The open XXZ-chain: Bosonisation, Bethe ansatz and logarithmic corrections

We calculate the bulk and boundary parts of the free energy for an open spin-1/2 XXZ-chain in the critical regime by bosonisation. We identify the cutoff independent contributions and determine their amplitudes by comparing with Bethe ansatz calculations at zero temperature T . For the bulk part of the free energy we find agreement with Lukyanov’s result [Nucl. Phys. B 522, 533 (1998)]. In the ...

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. ...

Bethe Ansatz for the Open Xxz Chain from Functional Relations at Roots of Unity

where σ , σ , σ are the standard Pauli matrices, η is the bulk anisotropy parameter, α± , β± , θ± are arbitrary boundary parameters, and N is the number of spins. Determining the energy eigenvalues in terms of solutions of a system of Bethe Ansatz equations is a fundamental problem, which has important applications in integrable quantum field theory as well as condensed matter physics and stati...

Heisenberg Model, Bethe Ansatz, and Random Walks