We propose an explicit expression for vacuum expectation values 〈eiaϕ〉 of the exponential fields in the sine-Gordon model. Our expression agrees both with semi-classical results in the sine-Gordon theory and with perturbative calculations in the massive Thirring model. We use this expression to make new predictions about the large-distance asymptotic form of the two-point correlation function in the XXZ spin chain.

arXiv:hep-th/9611238Nuclear Physics BJun 1, 1997385 citations

The European Physical Journal B

Perturbed sine-Gordon model: S=1/2 anisotropicxy chain with a longitudinal magnetic field

A. Rettori, Monica Macci�

Published Jun 1, 1987• 1 citation

Publisher

DOI: 10.1007/bf01303981

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by measuring the specific heat in magnetic fields. When this compound is subjected to a uniform magnetic field $\mathbit{H}$, a transverse staggered magnetic field $\mathbit{h}$ is induced in this compound owing to the staggered component of the $\mathbit{g}$ tensor and the Dzyaloshinskii-Moriya interaction with an alternating $\mathbit{D}$ vector. Consequently, the quantum sine-Gordon (SG) model is an effective model of this compound in a uniform magnetic field. In three different field directions, we observed a magnetic-field-induced gap, which increases with

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