Quantum mechanical picture of the coupling between interlayer electronic excitations and infrared active phonons in bilayer cuprate superconductors

TL;DR

This paper derives a formula for the c-axis infrared response in bilayer cuprate superconductors using diagrammatic perturbation theory, providing a more fundamental understanding of electron-phonon interactions.

Contribution

It introduces a diagrammatic derivation of the infrared response formula, advancing the theoretical framework for electron-phonon coupling in cuprates.

Findings

Derived the response formula from first principles

Enhanced understanding of electron-phonon interactions

Provides a basis for interpreting infrared spectra

Abstract

The formula frequently used to describe the c-axis infrared response of the coupled electron-phonon system of bilayer cuprate superconductors and providing important insights into the physics of these materials has been originally obtained at the level of the phenomenological multilayer model. Here we derive it using diagrammatic perturbation theory.