Ultrafast pump-probe spectroscopic signatures of superconducting and pseudogap phases in YBa2Cu3O7-{\delta} films

TL;DR

This study uses femtosecond pump-probe spectroscopy to identify optical signatures of superconducting and pseudogap phase transitions in YBa2Cu3O7-{ extdelta} films, revealing distinct transient behaviors associated with each phase.

Contribution

It demonstrates a method to distinguish superconducting and pseudogap phases via ultrafast optical measurements, removing thermal effects to clarify phase-specific dynamics.

Findings

Distinct optical signatures at TSC and TPG transitions.

Reduced reflectivity change in pseudogap phase.

Faster recovery time in pseudogap phase.

Abstract

Femtosecond pump-probe spectroscopy is applied to identify transient optical signatures of phase transitions in optimally doped YBa2Cu3O7-{\delta} films. To elucidate the dynamics of superconducting and pseudogap phases, the slow thermal component is removed from the time-domain traces of photo-induced reflectivity in a high-flux regime with low frequency pulse rate. The rescaled data exhibit distinct signatures of the phase separation with abrupt changes at the onsets of TSC and TPG in excellent agreement with transport data. Compared to the superconducting phase, the response of the pseudogap phase is characterized by the strongly reduced reflectivity change accompanied by a faster recovery time.