Cyclotron resonance (CR) measurements for the Fe-based superconductor KFe2As2 are performed. One signal for CR is observed, and is attributed to the two-dimensional α Fermi surface at the Γ point. We found a large discrepancy in the effective masses of CR [(3.4±0.05) me (me is the free-electron mass)] and de Haas-van Alphen results, a direct evidence of mass enhancement due to electronic correlation. A comparison of the CR and de Haas-van Alphen results shows that both intra- and interband electronic correlations contribute to the mass enhancement in KFe 2As2.
ASJC Scopus subject areas
- Physics and Astronomy(all)