Infrared Hall effect in high Tc superconductors: Evidence for non-Fermi liquid Hall scattering

TL;DR

This study measures infrared Faraday rotation and circular dichroism in high Tc superconductors, revealing a non-Fermi liquid behavior in Hall scattering that challenges existing theories of normal state transport.

Contribution

It provides experimental evidence of non-Fermi liquid Hall scattering in high Tc superconductors through infrared measurements.

Findings

Hall scattering rate varies as T^2 with temperature

Hall conductivity strongly depends on temperature

Hall scattering depends weakly on frequency

Abstract

Infrared (20-120 cm-1 and 900-1100 cm-1) Faraday rotation and circular dichroism are measured in high Tc superconductors using sensitive polarization modulation techniques. Optimally doped YBCO thin films are studied at temperatures down to 15 K and magnetic fields up to 8 T. At 1000 cm-1 the Hall conductivity varies strongly with temperature in contrast to the longitudinal conductivity which is nearly independent of temperature. The Hall scattering rate has a T^2 temperature dependence but, unlike a Fermi liquid, depends only weakly on frequency. The experiment puts severe constraints on theories of transport in the normal state of high Tc superconductors.