Nontrivial Edge Superconductivity in Dirac Superconductor PdTe2

Abstract Superconducting topological materials with coexisted superconductivities and topological boundary states are promising platforms for realizing intrinsic topological superconductivity. In this work, the superconducting type-II Dirac semimetal PdTe2 is shown to exhibit clear periodic critical current oscillations in perpendicular magnetic fields due to the fluxoid quantization, indicating the existence of edge superconductivity in PdTe2. Furthermore, a comparative study of the different superconducting properties of the bulk and edge of PdTe2 provides direct evidence for this edge superconductivity. More importantly, by a careful analysis of the flux penetration area, the nontrivial character of the edge superconductivity is revealed, i.e., the edge superconductivity appears not only at the physical boundary of the flake, but also at the interior interface between superconducting and normal regions of PdTe2. The emergence of nontrivial edge superconductivity, indicative of the putative bulk topological superconductivity, not only reveals the great potential of PdTe2 but also provides an experimental avenue for exploring intrinsic topological superconductivity by leveraging bulk-boundary correspondence.