Observation of Topological Superconductivity in a Stoichiometric Transition Metal Dichalcogenide 2M-WS2

Abstract

Topological superconductors (TSCs) are unconventional superconductors with bulk superconducting gap and in-gap Majorana states on the boundary that may be used as topological qubits for quantum computation. Despite their importance in both fundamental research and applications, natural TSCs are very rare. Here, combining state of the art synchrotron and laser-based angle-resolved photoemission spectroscopy, we investigated a stoichiometric transition metal dichalcogenide (TMD), 2M-WS2 with a superconducting transition temperature of 8.8 K (the highest among all TMDs in the natural form up to date) and observed distinctive topological surface states (TSSs). Furthermore, in the superconducting state, we found that the TSSs acquired a nodeless superconducting gap with similar magnitude as that of the bulk states. These discoveries not only evidence 2M-WS2 as an intrinsic TSC without the need of sensitive composition tuning or sophisticated heterostructures fabrication, but also provide an ideal platform for device applications thanks to its van der Waals layered structure.

Accepted by Nature Communications

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Cited by in corpus (22)

• Giant Nernst effect in the crossover between Fermi liquid and strange metal
• Coexistence of bulk-nodal and surface-nodeless Cooper pairings in a superconducting Dirac semimetal
• Direct observation of topological surface state in the topological superconductor 2M-WS2
• Realizing Topological Superconductivity in Tunable Bose-Fermi Mixtures with Transition Metal Dichalcogenide Heterostructures
• Topology hierarchy of transition metal dichalcogenides built from quantum spin Hall layers
• Superconductivity induced by gate-driven hydrogen intercalation in the charge-density-wave compound 1T-TiSe2
• Chemical Principles of Intrinsic Topological Superconductors
• Strong-Coupling Superconductivity with $T_c$ $\sim$ 10.8 K Induced by P Doping in the Topological Semimetal Mo${}_5$Si${}_3$
• Tuning multiple Landau Quantization in Transition-Metal Dichalcogenide with Strain
• Topological Superconductivity in Monolayer T${}_{\text{d}}$-MoTe${}_2$
• Crossover from Conventional to Unconventional Superconductivity in 2M-WS2
• Observation of spin-polarized surface states in a nodal line semimetal SnTaS${}_2$
• Identifying Majorana vortex modes via non-local transport
• Nonlinear optical responses in multi-orbital topological superconductors
• Anisotropic multiband superconductivity in 2M-WS${}_2$ probed by controlled disorder
• Prediction of topological superconductivity in 1$T$-TiTe${}_2$ under pressure
• Tunable superconductivity coexisting with the anomalous Hall effect in 1T'-WS2
• Ramp reversal memory in bulk crystals of 1T-TaS2
• Lattice-decoupled rotatable stripe-like charge order within the strange metal phase of 2M-WS2
• Re-entrant topological order in strongly correlated nanowire due to Rashba spin-orbit coupling
• Direct evidence for two-gap superconductivity in hydrogen-intercalated titanium diselenide
• Breaking the Trade-off: Bulk 2D Ising Superconductivity with High Tc and Giant Interlayer Spacing via a Unique Chain Intercalation in (BaS)1/3TaS2