Effect of Fermi Surface Nesting on Resonant Spin Excitations in Ba1-xKxFe2As2

J. -P. Castellan; S. Rosenkranz; E. A. Goremychkin; D. Y. Chung; I. S. Todorov; M. G. Kanatzidis; I. Eremin; J. Knolle; A. V. Chubukov; S. Maiti; M. R. Norman; F. Weber; H. Claus; T. Guidi; R. I. Bewley; R. Osborn

doi:10.1103/physrevlett.107.177003

arXiv · 1106.0771

Effect of Fermi Surface Nesting on Resonant Spin Excitations in Ba1-xKxFe2As2

J. -P. Castellan·S. Rosenkranz·E. A. Goremychkin·D. Y. Chung·I. S. Todorov·M. G. Kanatzidis·I. Eremin·J. Knolle·A. V. Chubukov·S. Maiti·M. R. Norman·F. Weber·H. Claus·T. Guidi·R. I. Bewley·R. Osborn

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Abstract

We report inelastic neutron scattering measurements of the resonant spin excitations in Ba1-xKxFe2As2 over a broad range of electron band filling. The fall in the superconducting transi- tion temperature with hole doping coincides with the magnetic excitations splitting into two incom- mensurate peaks because of the growing mismatch in the hole and electron Fermi surface volumes, as confirmed by a tight-binding model with s+- symmetry pairing. The reduction in Fermi surface nesting is accompanied by a collapse of the resonance binding energy and its spectral weight caused by the weakening of electron-electron correlations.

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J. -P. Castellan, S. Rosenkranz, E. A. Goremychkin, D. Y. Chung, I. S. Todorov, M. G. Kanatzidis, I. Eremin, J. Knolle, A. V. Chubukov, S. Maiti, M. R. Norman, F. Weber, H. Claus, T. Guidi, R. I. Bewley, R. Osborn. 2011-06-03. Effect of Fermi Surface Nesting on Resonant Spin Excitations in Ba1-xKxFe2As2. https://doi.org/10.1103/physrevlett.107.177003

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