Terahertz Hall Measurements On Optimally Doped Single Crystal Bi-2212

TL;DR

This study measures the infrared Hall angle in optimally doped Bi-2212 across a range of energies and temperatures, revealing discrepancies with ARPES data that are explained by a Fermi liquid model including electron-magnon interactions.

Contribution

It provides the first infrared Hall measurements on Bi-2212 and demonstrates that a Fermi liquid theory with vertex corrections explains the observed data.

Findings

Hall frequency is larger than ARPES-based expectations.

Temperature dependence of Hall angle follows a power law similar to dc measurements.

Fermi liquid model with electron-magnon scattering explains the results.

Abstract

The infrared Hall angle in optimally doped single crystal $\rm Bi_2 Sr_2 Ca Cu_2 O_{8+x}$ was measured from 3.05 to 21.75 meV as a continuous function of temperature from 25 to 300\,K. In the normal state, the temperature dependence of the real part of the cotangent of the infrared Hall angle obeys the same power law as dc measurements. The measured Hall frequency $\rm \omega_H$ is significantly larger than the expected value based upon ARPES data analyzed in terms of the relaxation time approximation. This discrepancy as well as the temperature dependence of $\rm Re(\cot{\theta_H})$ and $\omega_H$ is well described by a Fermi liquid theory in which current vertex corrections produced by electron-magnon scattering are included.