BCS-like Bogoliubov Quasiparticles in High-Tc Superconductors Observed by Angle-Resolved Photoemission Spectroscopy

TL;DR

This study uses high-resolution ARPES to observe Bogoliubov quasiparticles in a high-Tc superconductor, confirming BCS theory's applicability to cuprates' superconducting state.

Contribution

It provides direct experimental evidence of full quasiparticle dispersion and coherence factors in a high-Tc superconductor, validating BCS formalism in this context.

Findings

Observation of full energy dispersion of quasiparticles

Quantitative agreement with BCS theory predictions

Confirmation of BCS validity in cuprate superconductors

Abstract

We performed high-resolution angle-resolved photoemission spectroscopy on triple-layered high-Tc cuprate Bi2Sr2Ca2Cu3O10+delta. We have observed the full energy dispersion (electron and hole branches) of Bogoliubov quasiparticles and determined the coherence factors above and below EF as a function of momentum from the spectral intensity as well as from the energy dispersion based on BCS theory. The good quantitative agreement between the experiment and the theoretical prediction suggests the basic validity of BCS formalism in describing the superconducting state of cuprates.