The interplay between spin-orbit coupling and superconductivity in topologically nontrivial materials provides a fertile setting for realizing unconventional pairing states and Majorana bound modes. AuSn4, a noble metal stannide isostructural to PtSn4 and PdSn4, has recently been identified as a candidate two-dimensional superconductor exhibiting vortex core zero modes consistent with mixed s + p pairing symmetry. Here, we present a comprehensive study using angle-resolved photoemission spectroscopy (ARPES) and spin-resolved ARPES (SARPES), unveiling the coexistence of Rashba-split surface bands and Dirac nodal lines in AuSn4. We further identify a surface-confined van Hove singularity (VHS) in close proximity to the Dirac point near the Brillouin zone boundary. Together, these results position AuSn4 as a compelling superconducting platform within which Rashba type surface states and nontrivial topological bands reside, offering microscopic insight into the emergence of unconventional pairing and the prospects for topological superconductivity.
Deng et al. (Wed,) studied this question.