Doping dependent optical properties of Bi2201

TL;DR

This study investigates how doping influences the optical properties of Bi2201 cuprate superconductors, revealing a universal behavior in optical and electronic spectra explained by a doping-dependent electron-boson interaction.

Contribution

It provides a comprehensive analysis linking optical conductivity, self-energy, and electron-boson spectral function across doping levels in Bi2201, using a strong coupling formalism.

Findings

Optical spectra are well described by a doping-dependent electron-boson spectral function.

The spectral function shows strong doping dependence and weak temperature dependence.

A universal description of optical, ARPES, and tunneling spectra is proposed.

Abstract

An experimental study of the in-plane optical conductivity of (Pb$_{x}$,Bi$_{2-x}$)(La$_{y}$Sr$_{2-y}$)CuO$_{6+\delta}$ (Bi2201) is presented for a broad doping and temperature range. The in-plane conductivity is analyzed within a strong coupling formalism. We address the interrelationship between the optical conductivity ($\sigma(\omega)$), the single particle self energy, and the electron-boson spectral function. We find that the frequency and temperature dependence can be well described within this formalism. We present a universal description of optical, ARPES and tunneling spectra. The full frequency and temperature dependence of the optical spectra and single particle self-energy is shown to result from an electron-boson spectral function, which shows a strong doping dependence and weak temperature dependence.