Abstract
We report an angle-resolved photoemission spectroscopy study of a -type superconductor ( K) in the normal state. The resolved low-energy band structure mainly consists of several flat Fe bands, while the renormalization factors of different bands range from 1.7 to 2.8. Around the Fermi level, these bands contribute to a high density of states, which may account for the unusually high Sommerfeld coefficient . Besides, a 30 meV kink is observed, which is probably induced by electron-phonon interactions. Our results indicate that is a moderately correlated compound, while electron-phonon coupling should be taken into account to better understand its properties.
- Received 29 August 2015
- Revised 17 December 2015
DOI:https://doi.org/10.1103/PhysRevB.93.024506
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