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arXiv · 1501.02135

Non-Fermi-liquid scattering rates and anomalous band dispersion in ferropnictides

J. Fink·A. Charnukha·E. D. L. Rienks·Z. H. Liu·S. Thirupathaiah·I. Avigo·F. Roth·H. S. Jeevan·P. Gegenwart·M. Roslova·I. Morozov·S. Wurmehl·U. Bovensiepen·S. Borisenko·M. Vojta·B. Buechner
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Abstract

Angle-resolved photoemission spectroscopy (ARPES) is used to study the band dispersion and the quasiparticle scattering rates in two ferropnictides systems. Our ARPES results show linear-in-energy dependent scattering rates which are constant in a wide range of control parameter and which depend on the orbital character of the bands. We demonstrate that the linear energy dependence gives rise to weakly dispersing band with a strong mass enhancement when the band maximum crosses the chemical potential. In the superconducting phase the related small effective Fermi energy favors a Bardeen-Cooper-Schrieffer (BCS)\,\cite{Bardeen1957}-Bose-Einstein (BE)\,\cite{Bose1924} crossover state.

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J. Fink, A. Charnukha, E. D. L. Rienks, Z. H. Liu, S. Thirupathaiah, I. Avigo, F. Roth, H. S. Jeevan, P. Gegenwart, M. Roslova, I. Morozov, S. Wurmehl, U. Bovensiepen, S. Borisenko, M. Vojta, B. Buechner. 2015-01-09. Non-Fermi-liquid scattering rates and anomalous band dispersion in ferropnictides. https://doi.org/10.1103/physrevb.92.201106

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