Electron pockets and pseudogap Dirac point in underdoped cuprate superconductors

TL;DR

This paper models the pseudogap in underdoped cuprates, revealing electron pockets and a pseudogap Dirac point that influence spectroscopic data analysis, providing new insights into the electronic structure of these superconductors.

Contribution

It introduces a model that accounts for particle-hole asymmetry and predicts new vectors in the JDOS due to electron pockets, enhancing understanding of pseudogap phenomena.

Findings

Identification of new vectors in JDOS at positive bias

Prediction of a pseudogap Dirac point at positive bias

Correlation of Dirac point with FT-STS and ARPES data

Abstract

We consider a model of the pseudogap specifically designed to describe the underdoped cuprates and which exhibits particle-hole asymmetry. The presence of electron pockets, besides the usual hole pockets, leads to the appearance of new vectors beyond the usual so-called octet model in the joint density of states (JDOS), which underlies the analysis of Fourier-transform scanning tunneling spectroscopy (FT-STS) data. These new vectors are associated with distinct patterns of large amplitude in the JDOS and are expected to occur primarily at positive bias. Likewise a pseudogap Dirac point occurs at positive bias and this point can be determined either through FT-STS or through extrapolation of data from the autocorrelation function of angle-resolved photoemission spectroscopy.