Mixing of ground states in vertex models

We consider the analogue of the six-vertex model constructed from alternating spin n/2 and spin m/2 lines, where 1 = n < m. We identify the transfer matrix and the space on which it acts in terms of the representation theory of U_q (sl₂). We diagonalize the transfer matrix and compute the S-matrix. We give a trace formula for local correlation functions. When n = 1, the one-point function of a spin m/2 local variable for the alternating lattice with a particular ground state is given as a linear combination of the one-point functions of the pure spin m/2 model with different ground states. The mixing ratios are calculated exactly and are expressed in terms of irreducible characters of U_q(sl₂) and the deformed Virasoro algebra.