M. Idzumi, LEVEL-2 IRREDUCIBLE REPRESENTATIONS OF U(Q)(SL(2)), VERTEX OPERATORS,AND THEIR CORRELATIONS, International journal of modern physics A, 9(25), 1994, pp. 4449-4484
Vertex operators associated with level 2 U(q)(sl(2)) modules are expli
citly constructed using bosons and fermions. An integral formula is de
rived for the trace of products of vertex operators. These results are
applied to give n-point spin correlation functions of an integrable S
= 1 quantum spin chain, extending an earlier work of Jimbo et al. for
the case S = 1/2.