Unified description of cuprate superconductors by fractionalized electrons emerging from integrated analyses of photoemission spectra and quasiparticle interference

TL;DR

This paper demonstrates that a two-component fermion model effectively explains the electronic structure of cuprate superconductors by integrating ARPES and QPI spectroscopic data, supporting electron fractionalization.

Contribution

The study introduces a unified theoretical framework combining ARPES and QPI data with a two-component fermion model to explain cuprate electronic structures, highlighting electron fractionalization.

Findings

The two-component fermion model reproduces experimental ARPES and QPI data in full energy and momentum space.

QPI patterns characteristic of electron fractionalization are identified, distinct from conventional models.

The analysis resolves previous inconsistencies between ARPES and QPI data.

Abstract

Electronic structure of high-temperature superconducting cuprates is studied by analyzing experimental data independently obtained from two complementary spectroscopies, one, quasiparticle interference (QPI) measured by scanning-tunneling microscopy and the other, angle-resolved photoemission spectroscopy (ARPES) and by combining these two sets of data in a unified theoretical analysis. Through explicit calculations of experimentally measurable quantities, we show that a simple two-component fermion model (TCFM) representing electron fractionalization succeeds in reproducing various detailed features of these experimental data: ARPES and QPI data are concomitantly reproduced by the TCFM in full energy and momentum spaces. The measured QPI pattern reveals a signature characteristic of the TCFM, distinct from the conventional single-component prediction, supporting the validity of the electron fractionalization in the cuprate. The integrated analysis also solves the puzzles of ARPES and QPI data that are seemingly inconsistent with each other. The overall success of the TCFM offers a comprehensive understanding of the electronic structure of the cuprates. We further predict that a characteristic QPI pattern should appear in the unoccupied high-energy part if the fractionalization is at work. We propose that integrated-spectroscopy analyses offer a promising way to explore challenging issues of strongly correlated electron systems.