7 research outputs found
Cyclotron resonance and mass enhancement by electron correlation in KFeAs
Cyclotron resonance (CR) measurements for the Fe-based superconductor
KFeAs are performed. One signal for CR is observed, and is attributed
to the two-dimensional Fermi surface at the point. We found a
large discrepancy in the effective masses of CR [(3.40.05) ( is
the free electron mass)] and de-Haas van Alphen (dHvA) results, a direct
evidence of mass enhancement due to electronic correlation. A comparison of the
CR and dHvA results shows that both intra- and interband electronic
correlations contribute to the mass enhancement in KFeAs.Comment: 5 pages, 4 figure