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dc.contributor.authorYu, Rong
Wang, Zhentao
Goswami, Pallab
Nevidomskyy, Andriy H.
Si, Qimiao
Abrahams, Elihu
dc.date.accessioned 2013-03-14T18:08:25Z
dc.date.available 2013-03-14T18:08:25Z
dc.date.issued 2012
dc.identifier.citation Yu, Rong, Wang, Zhentao, Goswami, Pallab, et al.. "Spin dynamics of a J1- J2-K model for the paramagnetic phase of iron pnictides." Physical Review B, 86, (2012) American Physical Society: 85148. http://dx.doi.org/10.1103/PhysRevB.86.085148.
dc.identifier.urihttps://hdl.handle.net/1911/70611
dc.description.abstract We study the finite-temperature spin dynamics of the paramagnetic phase of iron pnictides within an antiferromagnetic J1-J2 Heisenberg model on a square lattice with a biquadratic coupling −K(Si · Sj )2 between the nearest-neighbor spins. Our focus is on the paramagnetic phase in the parameter regime of this J1-J2-K model where the ground state is a (π,0) collinear antiferromagnet. We treat the biquadratic interaction via a Hubbard-Stratonovich decomposition and study the resulting effective quadratic-coupling model using both modified spin wave and Schwinger boson mean-field theories; the results for the spin dynamics derived from the two methods are very similar. We show that the spectral weight of dynamical structure factor S(q,ω) is peaked at ellipses in the momentum space at low excitation energies.With increasing energy, the elliptic features expand towards the zone boundary and gradually split into two parts, forming a pattern around (π,π). Finally, the spectral weight is anisotropic, being larger along the major axis of the ellipse than along its minor axis. These characteristics of the dynamical structure factor are consistent with the recent measurements of the inelastic neutron scattering spectra of BaFe2As2 and SrFe2As2.
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 Spin dynamics of a J1- J2-K model for the paramagnetic phase of iron pnictides
dc.type Journal article
dc.contributor.funder National Science Foundation
dc.contributor.funder Welch Foundation
dc.citation.journalTitle Physical Review B
dc.citation.volumeNumber 86
dc.embargo.terms none
dc.type.dcmi Text
dc.identifier.doihttp://dx.doi.org/10.1103/PhysRevB.86.085148
dc.identifier.grantID DMR-1006985 (National Science Foundation)
dc.identifier.grantID C-1411 (Welch Foundation)
dc.type.publication publisher version
dc.citation.firstpage 85148


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