Anomalous Phonons in CaFe2As2

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dc.creatorMittal, R.
dc.creatorPintschovius, L.
dc.creatorLamago, D.
dc.creatorHeid, R.
dc.creatorBohnen, K. P.
dc.creatorReznik, D.
dc.creatorChaplot, S. L.
dc.creatorSu, Y.
dc.creatorKumar, N.
dc.creatorDhar, S. K.
dc.creatorThamizhavel, A.
dc.creatorBrueckel, Th.
dc.date2009-02-18
dc.date2009-05-08
dc.date.accessioned2026-07-07T13:18:05Z
dc.date.available2026-07-07T13:18:05Z
dc.descriptionExtensive inelastic neutron scattering measurements of phonons on a single crystal of CaFe2As2 allowed us to establish a fairly complete picture of phonon dispersions in the main symmetry directions. The phonon spectra were also calculated by density functional theory (DFT) in the local density approximation (LDA). There are serious discrepancies between calculations done for the optimized structure and experiment, because the optimised structure is not the ambient pressure structure but is very close to the collapsed structure reached at p = 3.5 kbar. However, if the experimental crystal structure is used the calculation gives correct frequencies of most phonons. The most important new result is that linewidths/frequencies of certain modes are larger/softer than predicted by DFT-LDA. We also observed strong temperature dependence of some phonons near the structural phase transition near 173K. This behavior may indicate anomalously strong electron phonon coupling and/or anharmonicity, which may be important to the mechanism of superconductivity.
dc.description12 pages, 3 figues Revised version, Final version, Accepted for publication in Physical Review Letters
dc.identifierhttps://arxiv.org/abs/0902.3181
dc.identifierhttp://arxiv.org/abs/0902.3181
dc.identifierPhysical Review Letters 102, 217001 (2009)
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/231318
dc.subjectSuperconductivity
dc.subjectMaterials Science
dc.titleAnomalous Phonons in CaFe2As2
dc.typetext

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