ac Josephson effect in a gate-tunable Cd3As2 nanowire superconducting weak link

Experimental signatures of topological superconductivity have been notoriously difficult to verify, even though they are actively being researched. Here, the authors use nanowires of Cd${}_{3}$As${}_{2}$ -- a Dirac semimetal -- to hunt for these signatures by simultaneously looking at Josephson radiation and Shapiro patterns at different doping levels. By cross-checking the experimental results with an extensive (RCSJ) model that includes thermal noise, it is concluded that trivial supercurrent dominates and that topological supercurrent, if existent, falls below the detection limit of the setup.