Normal-state magnetotransport in superconducting Tl2Ba2CuO6+δ to millikelvin temperatures

Abstract

We report a study of the normal-state Hall effect and magnetoresistance of single crystals of Tl2Ba2CuO6+δ. Using samples with Tc<15 K, we can suppress the superconductivity down to low temperatures with magnetic fields of 16 T, and can thus study the normal state properties over three decades of temperature, extending into the T→0 limit where it is possible to make a reliable estimate of kF∼0.7 Å−1 from the Hall effect in the elastic-scattering regime. The temperature dependence of the Hall coefficient, RH, below 30 K rules out models in which RH(T) is taken as a measure of a real temperature-dependent change in the carrier concentration. The two scattering rates (probed by the resistivity and the cotangent of the Hall angle) which characterize normal-state transport in the cuprates also appear in this overdoped material for T≥30 K. However, as T→0, we observe only a single scattering rate, whose temperature dependence is dominated by low power terms, in contrast to the T2 dependence predicted for a Fermi liquid. The relationship between these findings and anomalous behavior previously reported for the upper critical field is discussed. © 1996 The American Physical Society.

Source-reported materials — not catalogue approval

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