1.
Phys Rev Lett
; 107(16): 166402, 2011 Oct 14.
Article
in English
| MEDLINE
| ID: mdl-22107409
ABSTRACT
Cyclotron resonance (CR) measurements for the Fe-based superconductor KFe(2)As(2) 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)m(e) (m(e) 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(2)As(2).
2.
Phys Rev Lett
; 104(25): 259701; author reply 259702, 2010 Jun 25.
Article
in English
| MEDLINE
| ID: mdl-20867420