Doping-dependent optical properties of Bi2201

E Van Heumen,W Meevasana,D Van Der Marel,A B Kuzmenko,H Eisaki

doi:10.1088/1367-2630/11/5/055067

Abstract

An experimental study of the in-plane optical conductivity of (Pbx, Bi2−x)(LaySr2−y)CuO6+δ (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 (σ(ω)), 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, angle resolved photoemission spectroscopy (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.

Highlights

Many properties distinguish high temperature superconductors from conventional superconductors, most importantly the critical temperature
It is not surprising that experimental and theoretical efforts are aimed at finding alternatives for the conventional electron-phonon coupling driven pairing mechanism
The first school explains the peculiarities of these materials by strong correlation effects [1, 2, 3, 4, 5] while the second seeks the origin in the coupling of electrons to a spectrum of bosons [6, 7, 8, 9, 10]

Summary

Introduction

Many properties distinguish high temperature superconductors from conventional superconductors, most importantly the critical temperature. The first school explains the peculiarities of these materials by strong correlation effects [1, 2, 3, 4, 5] while the second seeks the origin in the coupling of electrons to a spectrum of bosons [6, 7, 8, 9, 10]. The resulting state of matter is not adiabatically connected to another well known state of matter, the Fermi liquid, its properties are fundamentally different. The second school starts by assuming that the underlying state of matter is a Fermi liquid but that the peculiar properties arise due to a strong coupling of electrons to bosons different from phonons in ordinary metals, for example spin fluctuations

Methods

Discussion

Conclusion