Order-by-disorder near criticality in XY pyrochlore magnets

We consider a system of spins on the sites of a three-dimensional pyrochlore lattice of corner-sharing tetrahedra interacting with a predominant effective xy exchange. In particular, we investigate the selection of a long-range ordered state with broken discrete symmetry induced by thermal fluctuati...

Full description

Saved in:
Bibliographic Details
Published in:Physical review. B, Condensed matter and materials physics Condensed matter and materials physics, 2015-05, Vol.91 (17)
Main Authors: Javanparast, Behnam, Day, Alexandre G R, Hao, Zhihao, Gingras, Michel J P
Format: Article
Language:English
Subjects:
Condensed matter
Exchange
Fluctuation
Lattices
Phase transformations
Pyrochlores
Three dimensional
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We consider a system of spins on the sites of a three-dimensional pyrochlore lattice of corner-sharing tetrahedra interacting with a predominant effective xy exchange. In particular, we investigate the selection of a long-range ordered state with broken discrete symmetry induced by thermal fluctuations near the critical region. At the standard mean-field theory (sMFT) level, in a region of the parameter space of this Hamiltonian that we refer to as [[gamma [sub 5]] region, the ordered state possesses an accidental U(1) degeneracy. Using a Ginzburg-Landau theory, we discuss the phenomenology of multiple phase transitions below the paramagnetic phase transition and within the [[gamma [sub 5]] long-range ordered phase.
ISSN:1098-0121
1550-235X
DOI:10.1103/PhysRevB.91.174424