Abstract
Fabrizio Nichele Monday, 10:40 - 11:10
Majorana modes in superconducting InAs/Al two-dimensional heterostructures
Majorana zero modes have received widespread attention due to their potential to support topologically protected quantum computing. Emerging as zero-energy states in one-dimensional semiconductors with induced superconductivity, Zeeman coupling, and spin-orbit interaction, Majorana modes have been primarily investigated in individual InSb or InAs nanowires, including recently realized epitaxial hybrid nanowires. Tests of non-Abelian statistics of Majoranas involve braiding or interferometric measurement, requiring branched geometries, which are challenging to realizing using nanowire growth. Scaling to large networks using arrays of assembled nanowire also appears difficult.
I will present investigations of Majorana zero modes in devices obtained from a two-dimensional heterostructure using top-down lithography and gating. Measurements indicate a hard superconducting gap, ballistic tunneling probes and in-plane critical fields up to 3 T. In the presence of an in-plane magnetic field aligned along the wire, zero energy states robust in field emerge out of coalescing Andreev bound states, indicative of Majorana zero modes. The Majorana peak height and width strongly depend on temperature, demonstrating weak coupling to the leads. Scalable top-down fabrication of high quality Majorana devices readily allows complex geometries and large networks, paving the way toward applications of Majorana devices.