  In two-dimensional lattice fermion model a determinant representation for the
two-point correlation function of the twist field in the disorder phase is
obtained. This field is defined by twisted boundary conditions for lattice
fermion field. The large distance asymptotics of the correlation function is
calculated at the critical point and in the scaling region. The result is
compared with the vacuum expectation values of exponential fields in the
sine-Gordon model conjectured by S.Lukyanov and A.Zamolodchikov.
