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dc.contributor.authorGoswami, Pallab
Si, Qimiao
dc.date.accessioned 2017-06-12T21:49:43Z
dc.date.available 2017-06-12T21:49:43Z
dc.date.issued 2014
dc.identifier.citation Goswami, Pallab and Si, Qimiao. "Topological defects of Néel order and Kondo singlet formation for the Kondo-Heisenberg model on a honeycomb lattice." Physical Review B, 89, no. 4 (2014) American Physical Society: https://doi.org/10.1103/PhysRevB.89.045124.
dc.identifier.urihttps://hdl.handle.net/1911/94832
dc.description.abstract Heavy-fermion systems represent a prototypical setting to study magnetic quantum phase transitions. A particular focus has been on the physics of Kondo destruction, which captures quantum criticality beyond the Landau framework of order-parameter fluctuations. In this context, we study the spin one-half Kondo-Heisenberg model on a honeycomb lattice at half filling. The problem is approached from the Kondo-destroyed, antiferromagnetically ordered insulating phase. We describe the local moments in terms of a coarse grained quantum nonlinear sigma model, and show that the skyrmion defects of the antiferromagnetic order parameter host a number of competing order parameters. In addition to the spin Peierls, charge and current density wave order parameters, we identify for the first time Kondo singlets as the competing orders of the antiferromagnetism. We show that the antiferromagnetism and various competing singlet orders can be related to each other via generalized chiral transformations of the underlying fermions. We also show that the conduction electrons acquire a Berry phase through their coupling to the hedgehog configurations of the Néel order, which cancels the Berry phase of the local moments. Our results demonstrate the competition between the Kondo singlet formation and spin-Peierls order when the antiferromagnetic order is suppressed, thereby shedding new light on the global phase diagram of heavy-fermion systems at zero temperature.
dc.language.iso eng
dc.publisher American Physical Society
dc.rights Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
dc.title Topological defects of Néel order and Kondo singlet formation for the Kondo-Heisenberg model on a honeycomb lattice
dc.type Journal article
dc.citation.journalTitle Physical Review B
dc.citation.volumeNumber 89
dc.citation.issueNumber 4
dc.type.dcmi Text
dc.identifier.doihttps://doi.org/10.1103/PhysRevB.89.045124
dc.type.publication publisher version
dc.citation.articleNumber 045124


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