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Author Cuccoli, A. ♦ Tognetti, V. ♦ Vaia, R. ♦ Verrucchi, P.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword PHYSICS ♦ ANTIFERROMAGNETISM ♦ HEISENBERG MODEL ♦ TEMPERATURE DEPENDENCE ♦ SPIN ♦ SELF-CONSISTENT FIELD ♦ EXCHANGE INTERACTIONS ♦ CORRELATIONS ♦ SQUARE LATTICES ♦ CORRELATION LENGTH
Abstract The quantum Heisenberg antiferromagnet (HAF) is approached by the {ital pure}-{ital quantum} {ital self}-{ital consistent} {ital harmonic} {ital approximation} that reduces it to an effective classical HAF model. The effective exchange, weakened by quantum fluctuations, enters the classical-like expression for thermal averages as a temperature scale, so that one can obtain in a simple way the quantum spin correlation length from its classical counterpart. For any spin value {ital S} the results compare very well with those from experiments, quantum Monte Carlo simulations, and high-{ital T} expansion. The adequacy of our theory and supports arguments previously raised against the quantitative validity of the mapping of the quantum HAF onto the quantum nonlinear sigma model. {copyright} {ital 1996 The American Physical Society.}
ISSN 00319007
Educational Use Research
Learning Resource Type Article
Publisher Date 1996-10-01
Publisher Place United States
Journal Physical Review Letters
Volume Number 77
Issue Number 16


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