Demonstration of Majorana Fermion Pairs in Superconducting gold Surface States*

We present strong evidence for the emergence of Majorana bound states (MBS) in gold nanowires with proximitized superconductivity, as theoretically predicted.¹ The interplay between superconductivity, spin-orbit coupling (SOC) and Zeeman field laid the foundation to realize MBS. We have experimentally achieved novel heterostructures, achieving these three interactions, and developed a unique method to fabricate such heterostructures into scalable nanowires. Using high-resolution scanning tunneling microscopy (STM) under in-plane magnetic field, we show that MBS appears in pairs at the opposite edges of a magnetic nanostructure on Au nanowire at 350 mK. Such spatially resolved pair of bound states, confirmed by further theoretical modeling, provides strong support for the observation of MBS in Au nanowire systems. It opens up the possibility for realizing MBS manipulations in stable and scalable metallic thin-film nanostructures, where strong SOC ensures much more robust MBS compared to other analogous semiconductor-based schemes.

1. A. C. Potter & P. A. Lee PRL 105, 227003 (2010); PRB 85, 094516 (2012)