Anomalous magnetoresistance and Hall current in the normal state of the cuprate superconductors

Abstract

Experiments on the normal-state Hall effect in YBa₂Cu₃O₇ and the normal-state magnetoresistance in Bi₂Sr₂CuO₆(Bi 2201) are described. The strong temperature dependence of the Hall resistivity is shown to derive from a 'Hall scattering rate' 1/Τ_H that varies as the square of temperature, in contrast to the transport scattering rate 1/Τ_tr. Scattering from zinc impurities increases both rates. We compare our results with a recent theory of Anderson. Low-temperature magnetoresistance (MR) has been used to extract the dephasing rate 1/Τ_φ in single-crystal Bi 2001. Between 0.4 and 20 K, 1/Τ_φ varies as T^1/3. We discuss the anomalous enhancement of the dephasing rate and implications for the usual quasi-particle picture. The MR in a longitudinal field shows novel features that do not fi t conventional interaction theory.