Diffusion of Nonequilibrium Quasiparticles in a Cuprate Superconductor

TL;DR

This study uses a transient grating technique to measure quasiparticle diffusion and scattering in a high-Tc cuprate superconductor, providing insights into their nonequilibrium dynamics.

Contribution

It introduces a novel application of transient grating measurements to determine quasiparticle diffusion and scattering rates in cuprate superconductors.

Findings

Measured quasiparticle diffusion coefficient.

Determined inelastic and elastic scattering rates.

Demonstrated technique’s potential for broader electronic systems.

Abstract

We report a transport study of nonequilibrium quasiparticles in a high-Tc cuprate superconductor using the transient grating technique. Low-intensity laser excitation (at photon energy 1.5 eV) was used to introduce a spatially periodic density of quasiparticles into a high-quality untwinned single crystal of YBa2Cu3O6.5. Probing the evolution of the initial density through space and time yielded the quasiparticle diffusion coefficient, and both inelastic and elastic scattering rates. The technique reported here is potentially applicable to precision measurement of quasiparticle dynamics, not only in cuprate superconductors, but in other electronic systems as well.