Comment on "The role of electron-electron interactions in two-dimensional Dirac fermions''

TL;DR

This paper critiques a previous study on Dirac fermions, highlighting that their reported Fermi velocity decrease is inconsistent with numerical data due to finite-size extrapolation issues.

Contribution

It provides a critical analysis of prior work, emphasizing the importance of proper finite-size extrapolation in studying electron interactions in Dirac fermions.

Findings

Previous results on Fermi velocity reduction are inconsistent with numerical data.

Finite-size effects significantly impact the interpretation of interaction effects.

Highlights the need for careful extrapolation methods in numerical studies.

Abstract

Tang et al. [Science 361, 570 (2018)] report on the properties of Dirac fermions with both on-site and Coulomb interactions. The substantial decrease up to ~40% of the Fermi velocity of Dirac fermions with on-site interaction is inconsistent with the numerical data near the Gross-Neveu quantum critical point. This results from an inappropriate finite-size extrapolation.