Nonequilibrium superconductivity in Y1-xPrxBa2Cu3O7 thin films

TL;DR

This study investigates the ultrafast conductivity dynamics in Y1-xPrxBa2Cu3O7 thin films using terahertz spectroscopy, revealing distinct recovery behaviors of superconducting pairs and quasiparticles and suggesting additional carrier relaxation pathways.

Contribution

It provides new insights into the frequency-dependent recovery of conductivity components and identifies an alternative carrier relaxation pathway in high-temperature superconductor thin films.

Findings

Recovery of real conductivity is faster than imaginary conductivity.

Imaginary conductivity recovery decreases with increasing frequency.

Evidence of an additional carrier relaxation pathway.

Abstract

We have measured the picosecond conductivity dynamics in Y1-xPrxBa2Cu3O7 thin films from 0.3-2.0 terahertz. Our experimental technique measures the complex conductivity $\sigma_{re}(\omega$) + i$\sigma_{im}(\omega$) permitting the simultaneous observation of superconducting pair and quasiparticle dynamics. We emphasize aspects of the conductivity dynamics which extend our previous results. In particular, the recovery of $\sigma_{re}$ is faster than $\sigma_{im}$, and the recovery of $\sigma_{im}$ decreases with increasing frequency. This suggests another carrier relaxation pathway, in addition to superconducting pair recovery, following optical excitation.