Evolution of a pairing-induced pseudogap from the superconducting gap of (Bi,Pb)2Sr2CuO6

TL;DR

This study uses high-resolution spectroscopy to investigate the pseudogap in a cuprate superconductor, revealing its persistence above Tc and its connection to the superconducting gap, supporting a pairing origin.

Contribution

It provides detailed momentum and temperature dependence of the pseudogap, demonstrating its evolution from the superconducting gap in (Bi,Pb)2Sr2CuO6.

Findings

Pseudogap persists well above Tc

Pseudogap smoothly connects to the superconducting gap

Pseudogap temperature scales with the superconducting gap

Abstract

We have performed an ultrahigh-resolution angle-resolved photoemission spectroscopy study of slightly-overdoped (Bi,Pb)2Sr2CuO6 to elucidate the origin of pseudogap. By using a newly developed xenon-plasma light source, we determined the comprehensive momentum and temperature dependences of the superconducting gap and the pseudogap. We found that the antinodal pseudogap persists far above the superconducting transition temperature and is smoothly connected to the nodal gap. The characteristic temperature of the pseudogap scales well with the superconducting-gap size irrespective of the momentum location. The present experimental results point to the pairing origin of the pseudogap.