FUSION OF THE Q-VERTEX OPERATORS AND ITS APPLICATION TO SOLVABLE VERTEX MODELS

摘要

We diagonalize the transfer matrix of the inhomogeneous vertex models of the 6-vertex type in the anti-ferroelectric regime directly in the infinite lattice. For this purpose we have introduced new types of q-vertex operators. The special cases of those transfer matrices were used to diagonalize the s-d exchange model [23, 1, 6]. New vertex operators are constructed from the level one vertex operators by the fusion procedure. Using this construction we determine the commutation relations among new vertex operators which play a crucial role for the diagonalization. In order to clarify the quasi-particle structure of the model we estabish new isomorphisms of crystals. The isomorphisms figure out, representation theoretically, the ground state degenerations. [References: 23]