Anisotropic pyrochlores and the global phase diagram of the checkerboard antiferromagnet

dc.creatorStarykh, Oleg A.
dc.creatorFurusaki, Akira
dc.creatorBalents, Leon
dc.date2005-03-11
dc.date2005-04-29
dc.date.accessioned2026-07-07T03:04:08Z
dc.date.available2026-07-07T03:04:08Z
dc.descriptionWe study the phase diagram of two models of spin-1/2 antiferromagnets composed of corner-sharing tetrahedra, the basis of the pyrochlore structure. Primarily, we focus on the Heisenberg antiferromaget on the checkerboard lattice (also called the planar pyrochlore and crossed-chains model). This model has an anisotropic limit, when the dimensionless ratio of two exchange constants, J_\times/J << 1, in which it consists of one-dimensional spin chains coupled weakly together in a frustrated fashion. Using recently developed techniques combining renormalization group ideas and one-dimensional bosonization and current algebra methods, we show that in this limit the model enters a crossed dimer state with two-fold spontaneous symmetry breaking but no magnetic order. We complement this result by an approximate ``quadrumer triplet boson'' calculation, which qualitatively captures the physics of the ``plaquette valence bond solid'' state believed to obtain for J_\times/J = 1. Using these known points in parameter space, the instabilities pointed to by the quadrumer boson calculation, and the simple limit J_\times/J >> 1, we construct a few candidate global phase diagrams for the model, and discuss the nature of the quantum phase transitions contained therein. Finally, we apply our quasi-one-dimensional techniques to an anisotropic limit of the three-dimensional pyrochlore antiferromagnet, an approximate model for magnetism in GeCu2O4. A crossed dimer state is predicted here as well.
dc.description19 pages, 7 figures; v2 corrected typos
dc.identifierhttps://arxiv.org/abs/cond-mat/0503296
dc.identifierhttp://arxiv.org/abs/cond-mat/0503296
dc.identifierPhys. Rev. B 72, 094416 (2005)
dc.identifierdoi:10.1103/PhysRevB.72.094416
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/26018
dc.subjectStrongly Correlated Electrons
dc.subjectStatistical Mechanics
dc.titleAnisotropic pyrochlores and the global phase diagram of the checkerboard antiferromagnet
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