Electrical Step‐Edge Contact to a Topological Superconductor Candidate 2M‐WS 2

Abstract A topological superconductor (TSC), characterized by a topologically nontrivial bulk state and protected gapless boundary states, is a promising platform for hosting Majorana bound states. However, many TSCs are environmentally sensitive, especially when thinned to 2D atomic layers. This instability poses a major challenge for integrating TSCs into electronic devices. Addressing it requires full encapsulation and high‐quality electrical contact to the TSC layer, which have not yet been achieved. Here, a novel contact geometry is demonstrated for an encapsulated topological superconductor candidate, 2M‐WS 2 , where metal electrodes contact the exposed step‐like edges with a width of only a few nanometers. This structure yields exceptionally low contact resistance ( R C ), down to ∼ 670 Ω·µm for a single unit and ∼ 65 Ω·µm for a six‐unit 2M‐WS 2 device. Below the superconducting critical temperature ( T C ), the TSC–metal interface becomes highly transparent, as evidenced by the Andreev reflection. Furthermore, the step‐edge contact prevents contamination during fabrication, enabling unprecedentedly high‐quality devices. In encapsulated 2M‐WS 2 , twofold rotational symmetry of the critical current ( I C ) and multiple anomalous peaks are observed in the differential resistance ( dV / dI ). The anisotropic I C originates from Fermi velocity variations along in‐plane lattice directions, while the anomalous peaks suggest multigap superconductivity in 2M‐WS 2 . These results reveal the intrinsic properties of 2M‐WS 2 and offer a new path toward high‐performance TSC‐based electronics.