Abstract
Temperature-dependent infrared reflectivity spectra of has been measured. A renormalized Drude peak with a heavy effective mass and a pronounced pseudogap of develops in the optical conductivity spectra at low temperatures. As the temperature decreases below , the effective mass rapidly increases, and the scattering rate is quenched. The temperature dependence of and indicates that the hybridization between the Fe spins and the charge carriers plays an important role in determining the physical properties of at low temperatures. This result is the clear evidence of the iron-based heavy quasiparticles.
- Received 10 April 2006
DOI:https://doi.org/10.1103/PhysRevB.73.214416
©2006 American Physical Society