Effect of spin fluctuations on the electronic structure in iron-based superconductors

Andreas Heimes, Roland Grein, Matthias Eschrig

Research output: Contribution to journalArticlepeer-review

Abstract

Magnetic inelastic neutron scattering studies of iron-based superconductors reveal a strongly temperature-dependent spin-fluctuation spectrum in the normal conducting state, which develops a prominent low-energy resonance feature when entering the superconducting state. Angle-resolved photoemission spectroscopy (ARPES) and scanning tunneling spectroscopy (STS) allow us to study the fingerprints of fluctuation modes via their interactions with electronic quasiparticles. We calculate such fingerprints in 122 iron pnictides using an experimentally motivated spin-fluctuation spectrum and make a number of predictions that can be tested in ARPES and STS experiments. This includes discussions of the quasiparticle scattering rate and the superconducting order parameter. In quantitative agreement with experiment we reproduce the quasiparticle dispersions obtained from momentum distribution curves as well as energy distribution curves. We discuss the relevance of the coupling between spin fluctuations and electronic excitations for the superconducting mechanism.
Original languageEnglish
Pages (from-to) 064528
Number of pages19
JournalPhysical Review B
Volume86
Issue number064528
DOIs
Publication statusPublished - 30 Aug 2012

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