Induced superconductivity and multiple Andreev reflections in multilayer WTe₂ Josephson junctions

Introducing superconductivity into topological materials has become a focus of attention in condensed matter physics as an effective way to realize Majorana modes. It has been predicted that Majorana bound states could arise from the proximity effect between an s-wave superconductor and the surface states of a strong topological insulator (TI). As one of the transition metal dichalcogenides, the topological properties of WTe₂ have been verified in both bulk (type-II Weyl semi-metal) and monolayer materials (topological insulator). Here we fabricated SNS junctions based on multilayer WTe₂ flakes. We report the observations of the proximity effect induced superconductivity revealed by magnetoresistance (MR) and I-V measurements. Distinct zero-bias conductance peaks in differential conductance measurements, might be as a sign of Majorana state, were also observed. In addition, the multi-dips of differential resistance at low temperature and magnetic field marks multiple Andreev reflections which might result from the intrinsic multi-gap superconducting states of WTe₂.