Theory Group Seminars

Bethe Ansatz and Coordinate Bethe Ansatz, application to three state Hamiltonians

by Luc Frappat

Europe/Rome
248 (Building C, first floor)

248

Building C, first floor

Description
Quantum integrable systems have a long history. Originally, solving such models was done through the Coordinate Bethe Ansatz, while the underlying mathematical structure was not manifest. In the eighties, the R-matrices, solutions of the celebrated Yang-Baxter equation, has become a cornerstone of the resolution of such systems. R-matrices contain the Hamiltonian of the system and constitute the basic ingredient of the Algebraic Bethe Ansatz that provides the eigenvalues and eigenfunctions of the model. After presenting and comparing the two ansatz, we review some of the strategies that can be implemented to infer an R-matrix from the knowledge of its Hamiltonian, and apply this framework to the case of three-state Hamiltonians with rank 1 symmetry and nearest-neighbour interactions in the context of spin chains.