Correlated double-Weyl semimetals with Coulomb interactions: possible applications to HgCr2Se4 and SrSi2

TL;DR

This paper investigates how Coulomb interactions affect double-Weyl fermions in 3D systems, revealing a transition to a stable fixed point with anisotropic screening and logarithmic corrections in measurable quantities, with implications for specific materials.

Contribution

It introduces a renormalization group analysis showing Coulomb interactions induce a nontrivial fixed point for double-Weyl fermions, affecting their physical properties.

Findings

Unstable fixed point flows to a stable anisotropic fixed point.

Logarithmic corrections to specific heat are predicted.

Implications for HgCr2Se4 and SrSi2 as double-Weyl materials.

Abstract

We study the fate of double-Weyl fermions in three-dimensional systems in the presence of long-range Coulomb interactions. By employing the momentum-shell renormalization group approach, we find that the fixed point of noninteracting double-Weyl fermions is unstable against Coulomb interactions and flows to a nontrivial stable fixed point with anisotropic screening effect. Moreover, experimentally measurable quantities such as specific heat obtain unusual logarithmic corrections. We also discuss implications of our results to three-dimensional materials HgCr2Se4 and SrSi2, candidate materials of hosting double-Weyl fermions.