Theory of time-resolved spectral function in high-temperature superconductors with bosonic modes

TL;DR

This paper introduces a three-temperature model for simulating electron and phonon dynamics in high-temperature superconductors, revealing how spectral features evolve over time and under laser excitation, indicating electron-vibration coupling.

Contribution

It develops a comprehensive three-temperature model that incorporates anisotropic electron-phonon interactions and superconducting states to analyze time-resolved spectral functions.

Findings

Dip-hump spectral features evolve with time delay.

Laser excitation induces new phononic structures.

Model captures anisotropic electron-phonon coupling effects.

Abstract

We develop a three-temperature model to simulate the time dependence of electron and phonon temperatures in high-temperature superconductors displaying strong anistropic electron-phonon coupling. This model not only takes the tight-binding band structure into account, but also is valid in superconducting state. Based on this model, we calculate the time-resolved spectral function via the double-time Green's functions. We find that the dip-hump structure evolves with the time delay. More interestingly, new phononic structures are obtained when the phonons are excited by a laser field. This signature may serve as a direct evidence for electron-vibration mode coupling.