Observation of chiral surface state in superconducting <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>NbGe</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:math>

The interplay between topology and superconductivity in quantum materials presents opportunities for exploring novel quantum phenomena. In this study, we investigate the topological properties and superconductivity of the nonsymmorphic chiral superconductor NbGe2 using high-resolution angle-resolved photoemission spectroscopy (ARPES), transport measurements, and calculations. The ARPES data revealed exotic chiral surface states on the (100) surface originating from the inherent chiral crystal structure. Our calculations suggest that NbGe2's electronic structure may include elusive Weyl fermions, highlighting its potential for topological superconductivity. Furthermore, we uncovered the signatures of van Hove singularities, which may enhance many-body interactions. Additionally, transport measurements demonstrated that NbGe2 exhibits superconductivity below 2K. Overall, our comprehensive results provide strong experimental evidence that NbGe2 is a promising platform for investigating the interplay between nontrivial band topology, possible Weyl fermions, vHSs, and superconductivity in chiral quantum materials. Published by the American Physical Society 2025