Signature of Majorana Zero Mode in Atomic Chains on Proximitized Bi(110) Surface*

Ferromagnetic chains of Fe atoms on top of a superconducting Pb substrate have proven to be a valuable platform to host Majorana zero modes(MZM) in different experiments[1,2,3]. Realizing new platforms, which combine ferromagnetism, strong Rashba spin-orbit coupling and superconductivity, is highly desirable to further study the emergence of MZM and to find systems with the largest topological gap. We have successfully grown expitaxial Bi(110) thin film on a superconducting substrate that shows robust proximity induced superconductivity with a hard gap. Examining the properties of such films in magnetic fields, we have visualized vortices and shown the persistence of surface superconductivity to fields above the bulk critical field. Introducing single magnetic atoms gives rise to Shiba states inside the superconducting gap on the Bi surface. Furthermore, we have successfully fabricated magnetic chains on the proximized Bi surface. Using high resolution spectroscopic measurements, we find distinct localized zero bias peaks at both ends, consistent with the formation of MZM in our atomic chains.

1. S. Nadj-Perge et al. Science (2014)
2. B.E. Feldman et al. Nature Physics (2017)
3. S. Jeon et al. Science (2017)