Asymmetric edge supercurrents in topological PdTe2 Josephson junctions

Searching for nontrivial boundary states is of particular interest in the study of higher-order band topology. Here, we report a systematic investigation of supercurrent interference phenomena in niobium-palladium ditelluride-niobium Josephson junctions. The comparative study of edge-touched and -untouched junctions provides compelling evidence for the existence of asymmetric edge supercurrents in palladium ditelluride. Notably, the edge supercurrent exhibits a significantly more rapid increase with decreasing temperatures than the bulk/surface supercurrents, suggesting the nontrivial character of the edge electronic states. These experimental results, along with first-principles calculations, support an asymmetric hinge state model, thereby establishing palladium ditelluride as a quantum material hosting both higher-order topology and superconductivity. The search for non-trivial boundary states is central to the study of higher-order band topology. Transport studies in superconducting Josephson junctions fabricated from PdTe2 reveal the presence of asymmetric edge states, establishing PdTe2 as a quantum material with both higher order topology and superconductivity.