Interplay between the pseudogap and superconductivity in HgBa$_2$CuO$_4$ single crystals

TL;DR

This study uses Electronic Raman Scattering to explore how the pseudogap and superconductivity interact in HgBa$_2$CuO$_4$ single crystals across different doping levels, revealing distinct behaviors of quasiparticles.

Contribution

It provides new insights into the doping-dependent dynamics of quasiparticles and proposes a model linking antinodal response suppression to competing phase fluctuations.

Findings

Antinodal quasiparticle response diminishes in underdoped regime.

Nodal quasiparticles show separate energy scales for pseudogap and superconducting gap.

Proposed model connects response suppression to fluctuations of a competing phase.

Abstract

We report a doping dependant Electronic Raman Scattering (ERS) study of HgBa$_2$CuO$_{4+\delta}$ (Hg-1201) single crystals. We investigate the dynamics of the antinodal and nodal quasiparticles. We show that the dynamical response of the antinodal quasiparticles is strongly reduced towards the underdoped regime in both the normal and superconducting states. When probing the nodal quasiparticles, we are able to distinguish between the energy scale of the pseudogap and that of the superconducting gap. A simple model relating the suppression of the dynamical response of the antinodal quasiparticles to fluctuations related to a competing phase is proposed.