Measurement of the Far Infrared Magneto-Conductivity Tensor of Superconducting YBa$_2$Cu$_3$O$_{7-\delta }$ Thin Films

TL;DR

This study measures the far infrared magneto-conductivity tensor of superconducting YBa₂Cu₃O₇−δ thin films in magnetic fields up to 14T, revealing the dominance of three key terms in the magneto-conductivity spectrum.

Contribution

It provides the first detailed measurement and analysis of the magneto-conductivity tensor of YBa₂Cu₃O₇−δ thin films in the far infrared range, identifying key spectral features.

Findings

Magneto-conductivity dominated by London and Lorentzian terms.

Identification of a low-frequency Lorentzian at ~3 cm⁻¹.

Detection of a finite frequency Lorentzian at 24 cm⁻¹.

Abstract

We report measurements of the far infrared transmission of superconducting YBa$_2$Cu$_3$O$_{7-\delta }$ thin films from 5 cm$^{-1}$ to 200 cm$^{-1}$ in fields up to 14$T$. A Kramers-Kronig analysis of the magneto-transmission spectrum yields the magneto-conductivity tensor. The result shows that the magneto-conductivity of YBa$_2$Cu$_3$O$_{7-\delta }$ is dominated by three terms: a London term, a low frequency Lorentzian ($\omega _1\approx $ 3 cm$% ^{-1}$) of width $\Gamma _1=$ 10 cm$^{-1}$ and a finite frequency Lorentzian of width $\Gamma _2=$ 17 cm$^{-1}$ at $\omega _2=$ 24 cm$^{-1}$ in the hole cyclotron resonance active mode of circular polarization.\\