The infrared Hall conductivity in optimally-doped BSCCO

TL;DR

This study measures the mid and far infrared Hall conductivity in optimally doped BSCCO, revealing a nearly Drude behavior in Hall response and contrasting scattering rates with longitudinal conductivity, supporting fluctuation-exchange models.

Contribution

It provides detailed frequency and temperature dependence of Hall transport in BSCCO, highlighting distinct behaviors from longitudinal conductivity and supporting theoretical models with vertex corrections.

Findings

Hall conductivity shows nearly Drude behavior unlike longitudinal conductivity.

Hall scattering rate increases linearly with temperature, small intercept at T=0.

Spectral weight of Hall conductivity is significantly suppressed compared to band value.

Abstract

he frequency dependence in the mid IR from 900 to 1100 cm$^{-1}$ and far IR at 84 cm$^{-1}$ and temperature dependence from 35 to 330 K of the normal state Hall transport is reported in single crystal, optimally doped Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$. The results show a nearly Drude behavior in the Hall conductivity $\sigma_{xy}$, which stands in contrast to the more complex extended Drude behavior for the longitudinal conductivity $\sigma_{xx}$. The mid IR Hall scattering rate increases linearly with temperature and has a small, positive, projected intercept of 200 cm$^{-1}$ at T=0. In contrast, the longitudinal scattering rate is much larger and exhibits very little temperature dependence. The spectral weight of $\sigma_{xy}$ is suppressed to 0.09 times the band value, whereas the spectral weight of $\sigma_{xx}$ is 0.33 times the band value. These disparate behaviors are consistent with calculations based on the fluctuation-exchange interaction when current vertex corrections are included.