Strong correlation effects and optical conductivity in electron doped cuprates

TL;DR

This paper models the spectral and optical properties of electron-doped cuprates across doping levels using a self-energy approach that includes spin and charge fluctuations, capturing key experimental features.

Contribution

It introduces a comprehensive self-energy calculation that accounts for doping-dependent correlation effects in electron-doped cuprates, explaining spectral and optical phenomena.

Findings

Identification of four subbands in spectral functions.

Persistence of incoherent features and remnant Mott gap at high doping.

Explanation of pseudogap features via in-gap state transitions.

Abstract

We demonstrate that most features ascribed to strong correlation effects in various spectroscopies of the cuprates are captured by a calculation of the self-energy incorporating effects of spin and charge fluctuations. The self energy is calculated over the full doping range of electron-doped cuprates from half filling to the overdoped system. The spectral function reveals four subbands, two widely split incoherent bands representing the remnant of the split Hubbard bands, and two additional coherent, spin- and charge-dressed in-gap bands split by a spin-density wave, which collapses in the overdoped regime. The incoherent features persist to high doping, producing a remnant Mott gap in the optical spectra, while transitions between the in-gap states lead to pseudogap features in the mid-infrared.