Quench-drive spectroscopy of cuprates

TL;DR

This paper models the non-equilibrium dynamics of cuprate superconductors under quench-drive spectroscopy, aiming to identify signatures of phase coherence and Higgs modes to better understand their complex phase diagram.

Contribution

It introduces a theoretical framework for analyzing time-resolved current responses in cuprates, focusing on signatures of phase coherence and collective modes in Fourier space.

Findings

Identification of transient higher harmonic modulation signatures.

Detection of Higgs mode oscillations.

Potential to distinguish between different phases of cuprates.

Abstract

Cuprates are d-wave superconductors which exhibit a rich phase diagram: they are characterized by superconducting fluctuations even above the critical temperature, and thermal disorder can reduce or suppress the phase coherence. However, photoexcitation can have the opposite effect: recent experiments have shown an increasing phase coherence in optimally doped BSCCO with mid-infrared driving. Time-resolved terahertz spectroscopies are powerful techniques to excite and probe non-equilibrium states of superconductors, directly addressing collective modes, such as amplitude (Higgs) oscillations. In this work, we calculate the full time evolution of the current generated by a cuprate with a quench-drive spectroscopy setup. Analyzing the response in Fourier space with respect to both the real time and the quench-drive delay time, we look for the signature of a transient modulation of higher harmonics as well as the Higgs mode, in order to characterize the ground state phase. In particular, this approach can provide a smoking gun for induced or increased phase coherence when applied to the pseudogap phase. These results can pave the way for future experimental schemes to characterize and study superconductors alongside incoherent phases and phase transitions, including induced and transient superconductivity.