The integrable XXZ Heisenberg model with arbitrary spin

Construction of the Hamiltonian, the ground-state configuration and conformal properties

verfasst von
Holger Frahm, Nai Chang Yu, Michael Fowler
Abstract

The construction of an integrable generalization of the antiferromagnetic XXZ Heisenberg model with arbitrary spin and easy plane anisotropy is reconsidered. The fusion procedure which has been used to generate models with spin S > 1 2 is shown to give hermitian operators corresponding to the physical conserved quantities only in certain (allowed) regions of the anisotropy γ. The forbidden regions coincide with those where Kirillov and Reshetikhin find restrictions on string locations in a formal Bethe ansatz analysis. In each of the allowed regions for the anisotropy there exists a unique ground-state configuration that does not change with γ. The critical behaviour of the S = 1 and S = 2 spin chains is investigated by numerical solution of their associated Bethe ansatz equations. Our results agree with the known decomposition of the spin model into the semidirect product of a free bosonic (gaussian) and a parafermionic (ZN) theory with N = 2S in the region of small anisotropy (γ < π/2S). They suggest that a similar decomposition holds in certain regions with γ > π/2S. Here, however, N is given by the integer part of π/γ.

Externe Organisation(en)
University of Virginia
Typ
Artikel
Journal
Nuclear Physics, Section B
Band
336
Seiten
396-434
Anzahl der Seiten
39
ISSN
0550-3213
Publikationsdatum
04.06.1990
Publikationsstatus
Veröffentlicht
Peer-reviewed
Ja
ASJC Scopus Sachgebiete
Physik der kondensierten Materie, Kern- und Hochenergiephysik, Mathematische Physik
Elektronische Version(en)
https://doi.org/10.1016/0550-3213(90)90435-G (Zugang: Unbekannt)