A.V.Puckov, P. Fournier, D.N. Basov,
T. Timusk, A. Kapitulnik, N.N.Kolesnikov.
Evolution of the pseudogap state of high-Tc
superconductors with doping.
We report on a study of the infrared properties
crystals at doping levels from underdoped to strongly overdoped.
We calculate the frequency-depended scattering rate 1/t(w,T)
and study its doping dependence. While we observe a normal-state gaplike
depression in 1/t(w,T)
in the underdoped regime, it is not observed in the overdoped regime. While
the high-frequency 1/t(w,T)
is temperature independent in the underdoped regime, it scales with temperature
in the overdoped regime.