Infrared optical response of strongly correlated cuprates: the effects of topological phase separation

TL;DR

This paper investigates how nanoscopic electron inhomogeneity and topological phase separation influence the infrared optical conductivity of cuprates, providing a model-based understanding of their complex optical responses.

Contribution

It introduces a simple model combining effective medium theory and quasiparticle approximation to describe static and dynamic phase separation effects in doped cuprates.

Findings

Static phase separation affects IR optical response.

Dynamic nanoscopic inhomogeneity influences low-frequency dynamics.

The model explains key features of optical conductivity in cuprates.

Abstract

We examine the effects of electron inhomogeneity on IR optical conductivity of cuprates. Nanoscopic electron inhomogeneity is believed to be inherent property of doped cuprates throughout the phase diagram beginning from electron-hole droplets in insulating parent system and ending by a topological phase separation in electron-hole bose liquid (EHBL) phase. A simple model of metal-insulator composite and effective medium theory has been used to describe the static phase separation effects. The low-frequency dynamics of topological EHBL phase in a random potential in underdoped regime has been discussed in a quasiparticle approximation within the memory function formalism. The effects of static and dynamic nanoscopic phase separation are believed to describe the main peculiarities of the optical response of doped cuprates in a wide spectral range.