In 1937 Ettore Majorana pointed out that unlike the standard solution of the Dirac equation which led to the electron and its antiparticle, the positron, it is possible to have a solution where the fermionic particle is its own antiparticle. While such a particle remains elusive in particle physics, a pair of localized Majorana states has been predicted to reside at the ends of a specially designed superconducting wire. These Majorana zero modes can form building blocks of qubits for fault-tolerant quantum computers. Here we report signatures of Majorana zero modes in a platform consisting of EuS and gold films grown on vanadium. This platform is amenable to standard nanofabrication techniques and holds promise for scalable Majorana qubits.

Abstract

Under certain conditions, a fermion in a superconductor can separate in space into two parts known as Majorana zero modes, which are immune to decoherence from local noise sources and are attractive building blocks for quantum computers. Promising experimental progress has been made to demonstrate Majorana zero modes in materials with strong spin–orbit coupling proximity coupled to superconductors. Here we report signatures of Majorana zero modes in a material platform utilizing the surface states of gold. Using scanning tunneling microscope to probe EuS islands grown on top of gold nanowires, we observe two well-separated zero-bias tunneling conductance peaks aligned along the direction of the applied magnetic field, as expected for a pair of Majorana zero modes. This platform has the advantage of having a robust energy scale and the possibility of realizing complex designs using lithographic methods.