T2-dependence of inverse Hall mobility observed in overdoped Tl-cuprates

Temperature dependences of the resistivity ρ and the Hall coefficient RH for overdoped Tl2Ba2CuO6+δ (Tl-2201) and Tl-Sr2CaCu2O7-δ (Tl-1212) are analyzed in terms of the inverse Hall mobility μH-1 = ρ/RH. The temperature dependence of μH-1 shows a clear T2-dependence for the entire carrier concentration range from high-Tc superconductor to overdoped normal metal. This is in sharp contrast to the complicated temperature dependences of both ρ and RH. These facts strongly suggest that the carrier concentration is variable with temperature as indicated by RH, whereas the scattering rate is always associated with a single scattering mechanism being ∝ T2. In that case, many ''anomalous'' normal state properties will disappear, and a rather simple single-band Fermi liquid picture emerges. (orig.)