The Role of Lattice Coupling in Establishing Electronic and Magnetic Properties in Quasi-One-Dimensional Cuprates

TL;DR

This study uses high-resolution resonant inelastic x-ray scattering to directly measure electron-lattice coupling in quasi-1D cuprates, revealing its influence on magnetic interactions and electronic properties.

Contribution

It provides the first direct measurement of site-dependent electron-lattice coupling and its impact on bond angles and magnetic interactions in quasi-1D cuprates.

Findings

Electron-lattice coupling causes doping-dependent bond angle distortions.

Lattice vibrations are directly linked to electronic excitations.

Lattice degrees of freedom significantly influence electronic behavior.

Abstract

High resolution resonant inelastic x-ray scattering has been performed to reveal the role of lattice-coupling in a family of quasi-1D insulating cuprates, Ca$_{2+5x}$Y$_{2-5x}$Cu$_5$O$_{10}$. Site-dependent low energy excitations arising from progressive emissions of a 70 meV lattice vibrational mode are resolved for the first time, providing a direct measurement of electron-lattice coupling strength. We show that such electron-lattice coupling causes doping-dependent distortions of the Cu-O-Cu bond angle, which sets the intra-chain spin exchange interactions. Our results indicate that the lattice degrees of freedom are fully integrated into the electronic behavior in low dimensional systems.