The thermodynamic limit and the finite-size behaviour of the fundamental Sp(2N) spin chain

This paper is concerned with the study of the fundamental integrable Sp(2N) spin chain. The Bethe ansatz equations are solved by special string structure which allows us to determine the bulk limit properties. We present evidences that the critical properties of the system are governed by the product of N c=1 conformal field theories and therefore different from that of the Sp(2N) Wess-Zumino-Witten theory. We argue that many of our findings can be generalized to include anisotropic symplectic spin chains. The possible relevance of our results to the physics of the spin-orbital spin chains are also discussed