Abstract
The downward shift of the electron chemical potential with hole doping in has been deduced from the shifts of photoemission and inverse-photoemission spectra. While the shift is large ( 1.5 eV/hole) in overdoped samples, it is suppressed ( eV/hole) in underdoped samples, implying a divergent charge susceptibility near the metal-insulator transition. In the overdoped regime, the and the electronic specific heat coefficient are consistently explained within Fermi-liquid theory, whereas the same analysis gives unphysical results in the underdoped regime, indicating the breakdown of the Fermi-liquid picture in the underdoped regime.
- Received 6 January 1997
DOI:https://doi.org/10.1103/PhysRevLett.79.2101
©1997 American Physical Society