Superconductivity in type II layered Weyl semi-metals

TL;DR

This paper investigates superconductivity in type II layered Weyl semimetals, specifically MoTe2, explaining experimental phenomena through a phonon pairing theory that considers Coulomb interactions and topological features.

Contribution

It develops a phonon-based pairing theory for layered Weyl semimetals that accounts for Coulomb effects and topological distinctions, explaining experimental observations.

Findings

Gate voltage does not affect Tc across a wide density range.

Interlayer distance significantly influences superconductivity.

The theory applies broadly to type II topological materials.

Abstract

Novel quasi two dimensional typically layered semimetals offer a unique opportunity to control the density and even the topology of the electronic matter. In intercalated MoTe2 type II Weyl semimetal the tilt of the dispersion relation cones is so large that topologically of the Fermi surface is distinct from a more conventional type I. Superconductivity observed recently in this compound [Zhang et al, 2D Materials 9, 045027 (2022)] demonstrated two puzzling phenomena: the gate voltage has no impact on critical temperature, Tc, in wide range of density, while it is very sensitive to the interlayer distance. The phonon theory of pairing in a layered Weyl material including the effects of Coulomb repulsion is constructed and explains the above two features in MoTe2.The first feature turns out to be a general one for any type II topological material, while the second reflects properties of the intercalated materials affecting the Coulomb screening.