Order by distortion and string modes in pyrochlore antiferromagnet

Preprint

30 August 2001

preprint
Published by arXiv in arXiv

https://doi.org/10.48550/arXiv.cond-mat/0108505

Abstract

We study the effects of magnetoelastic couplings on pyrochlore antiferromagnets. We employ Landau theory, extending an investigation begun by Yamashita and Ueda for the case of S=1, and semiclassical analyses to argue that such couplings generate bond order via a spin--Peierls transition. This is followed by, or concurrent with, a transition into one of several possible low-temperature Neel phases, with most simply collinear, but also coplanar or mixed spin patterns. In a collinear Neel phase, a dispersionless string-like magnon mode dominates the resulting excitation spectrum, providing a distinctive signature of the parent geometrically frustrated state. We comment on the experimental situation.

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All Related Versions

Version 1, 2001-08-30, ArXiv
Published version: Physical Review Letters, 88 (6), 067203.

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