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arXiv · 0903.1568

Theory of Magnetic Fluctuations in Iron Pnictides

L. Craco·M. S. Laad
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Abstract

Magnetic fluctuations in an unconventional superconductor (U-SC) can distinguish between distinct proposals for the symmetry of the order parameter. Motivated thereby, we undertake a study magnetic fluctuations in Iron pnictides, tracking their evolution from the incoherent normal, pseudogapped metal, to the U-SC state. Within our proposal of extended-s-plus s_{xy} inplane gap with proximity-induced out-of-plane line nodes, (i) we describe the evolution of the spin-lattice relaxation rate, from a non-Korringa form in the normal state, to a power-law form in the U-SC in good agreement with experiment, and (ii) we predict a sharp resonance in the U-SC state along (\pi,\pi), but not along (\pi/2,0), along with modulated c-axis intensity in inelastic neutron scattering work as a specific and testable manifestation of our proposal.

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L. Craco, M. S. Laad. 2009-03-09. Theory of Magnetic Fluctuations in Iron Pnictides. https://doi.org/10.1103/physrevb.80.054520

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