Reshaped Weyl fermionic dispersions driven by Coulomb interactions in MoTe2

TL;DR

This study provides direct evidence that Coulomb interactions significantly modify the electronic band structure of MoTe2, a Weyl semimetal, revealing a transition between type-I and type-II Weyl fermions influenced by doping.

Contribution

It demonstrates how Coulomb interactions alter Weyl fermionic dispersions in MoTe2 and explains quantum oscillation experiments through these effects.

Findings

Coulomb interactions modify quasiparticle bands in MoTe2

Evidence of a transition between type-I and type-II Weyl fermions

Quantum oscillation data explained by Coulomb-driven band changes

Abstract

We report the direct evidence of impacts of the Coulomb interaction in a prototypical Weyl semimetal, MoTe2, that alter its bare bands in a wide range of energy and momentum. Our quasiparticle interference patterns measured using scanning tunneling microscopy are shown to match the joint density of states of quasiparticle energy bands including momentum-dependent self-energy corrections, while electronic energy bands based on the other simpler local approximations of the Coulomb interaction fail to explain neither the correct number of quasiparticle pockets nor shape of their dispersions observed in our spectrum. With this, we predict a transition between type-I and type-II Weyl fermions with doping and resolve its disparate quantum oscillation experiments, thus highlighting the critical roles of Coulomb interactions in layered Weyl semimetals.