Fabrication of Low Disorder In-Plane PbSnTe Nanowire Devices for Topological Quantum Applications

Hybrid semiconductor-superconductor nanowires are promising building blocks for quantum information processing. However, disorder has been proven to be a limiting factor in conclusively revealing topological phenomena in electronic transport. In addition, scalable and intricate device architectures are required to achieve unambiguous signatures of topology. In this work, we present the selective area growth (SAG) of large-scale lead tin telluride (PbSnTe) nanowire networks combined with full in-situ device fabrication in ultra high vacuum using molecular beam epitaxy. This newly developed approach avoids fabrication-induced disorder, allowing for pristine interfaces and surfaces. PbSnTe, a group IV-VI rock-salt semiconductor and predicted topological crystalline insulator, is highly suited for quantum applications due to its large dielectric constant, strong spin-orbit coupling, and high carrier mobility. Our new and generalizable method could contribute to studying the intrinsic transport properties of topological materials.