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Title: The magnetoelastic mechanism of singlet phase formation in a two-dimensional quantum antiferromagnet

Abstract

A model describing the second-order phase transition with respect to the magnetoelastic coupling parameter from the antiferromagnetic (AFM) to the singlet state in a two-dimensional quantum magnet on a square lattice is proposed. The spectrum of elementary excitations in the singlet and AFM phases is calculated using an atomic representation, and the evolution of transverse and longitudinal branches of this spectrum is studied in the vicinity of the transition point. It is established that the AFM to singlet phase transition is related to softening of the longitudinal branch of oscillations. In the singlet phase, the gap plays the role of a parameter characterizing the distance to the phase transition point. It is shown that the spectrum of transverse oscillations in the AFM phase corresponds to the Goldstone boson. Based on an analysis of the stability of the spectrum of elementary excitations, a phase diagram is constructed that determines the regions of the existence of phases with plaquette-deformed lattices.

Authors:
; ;  [1]
  1. Russian Academy of Sciences, Institute of Physics, Siberian Division (Russian Federation)
Publication Date:
OSTI Identifier:
21067743
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Experimental and Theoretical Physics; Journal Volume: 102; Journal Issue: 2; Other Information: DOI: 10.1134/S106377610602004X; Copyright (c) 2006 Nauka/Interperiodica; Article Copyright (c) 2006 Pleiades Publishing, Inc; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ANTIFERROMAGNETISM; GOLDSTONE BOSONS; MAGNETS; NANOSTRUCTURES; OSCILLATIONS; PHASE DIAGRAMS; PHASE TRANSFORMATIONS; TETRAGONAL LATTICES; TWO-DIMENSIONAL CALCULATIONS

Citation Formats

Val'kov, V. V., E-mail: vvv@iph.krasn.ru, Mitskan, V. A., and Petrakovskii, G. A. The magnetoelastic mechanism of singlet phase formation in a two-dimensional quantum antiferromagnet. United States: N. p., 2006. Web. doi:10.1134/S106377610602004X.
Val'kov, V. V., E-mail: vvv@iph.krasn.ru, Mitskan, V. A., & Petrakovskii, G. A. The magnetoelastic mechanism of singlet phase formation in a two-dimensional quantum antiferromagnet. United States. doi:10.1134/S106377610602004X.
Val'kov, V. V., E-mail: vvv@iph.krasn.ru, Mitskan, V. A., and Petrakovskii, G. A. Wed . "The magnetoelastic mechanism of singlet phase formation in a two-dimensional quantum antiferromagnet". United States. doi:10.1134/S106377610602004X.
@article{osti_21067743,
title = {The magnetoelastic mechanism of singlet phase formation in a two-dimensional quantum antiferromagnet},
author = {Val'kov, V. V., E-mail: vvv@iph.krasn.ru and Mitskan, V. A. and Petrakovskii, G. A.},
abstractNote = {A model describing the second-order phase transition with respect to the magnetoelastic coupling parameter from the antiferromagnetic (AFM) to the singlet state in a two-dimensional quantum magnet on a square lattice is proposed. The spectrum of elementary excitations in the singlet and AFM phases is calculated using an atomic representation, and the evolution of transverse and longitudinal branches of this spectrum is studied in the vicinity of the transition point. It is established that the AFM to singlet phase transition is related to softening of the longitudinal branch of oscillations. In the singlet phase, the gap plays the role of a parameter characterizing the distance to the phase transition point. It is shown that the spectrum of transverse oscillations in the AFM phase corresponds to the Goldstone boson. Based on an analysis of the stability of the spectrum of elementary excitations, a phase diagram is constructed that determines the regions of the existence of phases with plaquette-deformed lattices.},
doi = {10.1134/S106377610602004X},
journal = {Journal of Experimental and Theoretical Physics},
number = 2,
volume = 102,
place = {United States},
year = {Wed Feb 15 00:00:00 EST 2006},
month = {Wed Feb 15 00:00:00 EST 2006}
}
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