A reevaluation of the coupling to a bosonic mode of the charge carriers in (Bi,Pb)$_2$Sr$_2$CaCu$_2$O$_{8+\delta} $ at the antinodal point

TL;DR

This study uses ARPES to analyze the spectral function of a high-Tc superconductor, revealing strong coupling to a magnetic resonance mode and providing a more accurate estimate of the coupling strength of charge carriers.

Contribution

It offers a reevaluation of ARPES data to better determine the coupling strength between charge carriers and a bosonic mode in a high-Tc superconductor.

Findings

Strong coupling to magnetic resonance mode identified

Bandwidth renormalization by a factor of two observed

More reliable coupling strength estimation achieved

Abstract

Angle-resolved photoemission spectroscopy (ARPES) is used to study the spectral function of the optimally doped high-T$_c$ superconductor (Bi,Pb)$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ in the vicinity of the antinodal point in the superconducting state. Using a parameterized self-energy function, it was possible to describe both the coherent and the incoherent spectral weight of the bonding and the antibonding band. The renormalization effects can be assigned to a very strong coupling to the magnetic resonance mode and at higher energies to a bandwidth renormalization by a factor of two, probably caused by a coupling to a continuum. The present reevaluation of the ARPES data allows to come to a more reliable determination of the value of the coupling strength of the charge carriers to the mode. The experimental results for the dressing of the charge carriers are compared to theoretical models.