A Crossroads for Electrons by Brennan Dizdar, 2024 Winner
A multitude of superconducting electrodes converge into a micron-sized trap for single electrons levitating on liquid helium. Electrons travel along a superfluid capillary channel and are confined above the end of a superconducting resonator, forming the basis for a levitating electron qubit. The device is a veritable tour of the PNF: 4 lithography steps, 3 etches, and 2 depositions all for 1 electron.