Electron-phonon coupling in 122 Fe pnictides analyzed by femtosecond time-resolved photoemission

TL;DR

This study uses femtosecond time-resolved photoemission to compare methods for measuring electron-phonon coupling in 122 Fe pnictides, finding weak coupling and suggesting electron-phonon interactions are unlikely to cause superconductivity.

Contribution

It systematically compares three measurement methods for electron-phonon coupling in 122 Fe pnictides, providing consistent results and insights into their superconducting mechanisms.

Findings

Electron-phonon coupling constant {1} < 0.2 in Eu and Ba-based 122 FeAs compounds

Good agreement among three different measurement methods

Weak electron-phonon coupling suggests it is unlikely to mediate superconductivity

Abstract

Based on results from femtosecond time-resolved photoemission, we compare three different methods for determination of the electron-phonon coupling constant {\lambda} in Eu and Ba-based 122 FeAs compounds. We find good agreement between all three methods, which reveal a small {\lambda} < 0.2. This makes simple electron-phonon mediated superconductivity unlikely in these compounds.