Double-time Green's functions are used within a mean-field treatment of the two-sublattice Ising model in a transverse field. In contrast to previous treatments, a correct version of the spectral theorem is used to obtain a correct mean-field treatment for all spin. In particular, the dielectric constant is obtained for S=1. The results are markedly different from those of earlier treatments and are readily extended to four-sublattice models.

Physical review. B, Condensed matterJun 1, 19912 citations

physica status solidi (b)

Commutator and Anticommutator Green Functions in the Ising Model with Transverse Field

V. L. Aksionov, Henryk Konwent, Juergen Schreiber

Published Jul 1, 1978• 1 citation

Publisher

DOI: 10.1002/pssb.2220880154

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T=0

where they appear to be related to those of the Ising model in one higher dimension.