Influence of Optically Quenched Superconductivity on Quasiparticle Relaxation Rates in Bi2Sr2CaCu2O8+delta

TL;DR

This study investigates how optically quenched superconductivity affects quasiparticle relaxation rates in Bi2Sr2CaCu2O8+delta using time- and angle-resolved photoemission, revealing fluence-dependent femtosecond and picosecond dynamics.

Contribution

It provides new insights into the influence of transient electronic structures on quasiparticle relaxation during nonequilibrium phase transitions.

Findings

Femtosecond dynamics emerge at high fluence.

Closure of the near-nodal gap is a key mechanism.

Transient electronic structure significantly affects relaxation rates.

Abstract

We use time- and angle-resolved photoemission to measure quasiparticle relaxation dynamics across a laser-induced superconducting phase transition in Bi2Sr2CaCu2O8+delta. Whereas low-fluence measurements reveal picosecond dynamics, sharp femtosecond dynamics emerge at higher fluence. Analyses of data as a function of energy, momentum, and doping indicate that the closure of the near-nodal gap and disruption of macroscopic coherence are primary mechanisms driving this onset. The results demonstrate the important influence of transient electronic structure on relaxation dynamics, which is relevant for developing an understanding of nonequilibrium phase transitions.