Achievement

Heavy metals, such as Au, Ag, and Pb, often have sharp surface states that are split by strong Rashba spin-orbit coupling. The strong spin-orbit coupling and two-dimensional nature of these surface states make them ideal platforms for realizing topological superconductivity and Majorana fermions. iQuISE IGERT Trainee Andrew Potter, working together with faculty member Patrick Lee, present a proposal to realize Majorana fermions at the ends of quasi-one-dimensional metallic wires. They show how superconductivity can be induced on the metallic surface states by a combination of proximity effect, disorder, and interactions. Applying a magnetic field along the wire can drive the wire into a topologically nontrivial state with Majorana end states. The parallel field Majorana fermions can be realized for an arbitrarily large chemical potential, which is controllable by gating. This idea may be realized by an Au(111) film deposited on a conventional superconductor.