 Hybrid structures consisting of a superconductor and a two-dimensional topological insulator can lead to topological superconductivity. Plainer Josephson junctions made from these materials were investigated using superconducting interference patterns. The patterns were found to be significantly different depending on whether or not the CD3AS2 film extended beyond the device. This suggests that the supercurrent is more distributed when the film extends beyond the device. Possible explanations for this behavior include edge states in the CD3AS2 film and the presence of a supercurrent channel formed by the superconductor. This article was authored by Armin Rashidi, Robert Kielhofer, Alexander C. Ligo, and others.