Abstract
Optical spectra have been systematically investigated for with various rare earth ions ( , Pr, Nd, Sm, and Y) as a typical three-dimensional correlated electron system, in which both the electon-correlation strength ( ) and the band filling ( ) can be varied. With a decrease of from 1, the spectrum of the Mott-gap excitation collapses and the Drude part evolves. We found that the rate of the Drude-part evolution with the nominal hole-doping level ( ) is critically enhanced as approaches the critical value for the bandwidth-controlled Mott transition.
- Received 14 February 1995
DOI:https://doi.org/10.1103/PhysRevLett.75.3497
©1995 American Physical Society