Realization of low-energy Dirac fermions in (Ir$_{1-x}$Pt$_x$)Te$_2$ superconductors

TL;DR

This paper demonstrates that in (Ir$_{1-x}$Pt$_x$)Te$_2$ superconductors, type-II Dirac points can be tuned to the Fermi level via element substitution, enabling the exploration of topological superconductivity.

Contribution

It reports the realization of low-energy Dirac fermions in (Ir$_{1-x}$Pt$_x$)Te$_2$, linking topological states with superconductivity through element substitution.

Findings

Dirac points are tuned to EF at x ~ 0.1

Superconductivity appears near 2 K in the doped compound

Potential for studying topological superconductivity

Abstract

Superconducting and topological states are two distinct quantum states of matter. Superconductors with topologically nontrivial electronic states provide a platform to study the interplay between them. Recent study revealed that a bulk superconductor PdTe2 is a topological Dirac semimetal with type-II Dirac fermions. However, the Dirac fermions in PdTe2 have no contribution to the superconducting pair because the Dirac points reside far below the Fermi level (EF). Here, we show that in the isostructural compounds (Ir1-xPtx)Te2, the type-II Dirac points can be adjusted to EF by element substitution at x ~ 0.1, for which the bulk superconductivity appears near 2 K. The (Ir1-xPtx)Te2 superconductor with the Dirac points at EF paves the way for studying the relevant exotic physical phenomena such as topological superconductivity in Dirac semimetals.