Non-Destructive Laser Nanopatterning of Superconducting Heterostructures in Topological Sn Thin Films

Heterostructures composed of superconductors and topological materials have emerged as compelling platforms for realizing topological superconductivity and fault-tolerant quantum computation. A critical bottleneck, however, lies in achieving atomically clean and structurally coherent interfaces between dissimilar materials. Here, we report the fabrication of high-quality planar heterostructures composed of the topological Dirac semimetal (TDS) α-Sn and the superconducting β-Sn phase, achieved by focused laser irradiation on α-Sn thin films. The irradiated regions undergo a phase transition from α-Sn to β-Sn, exhibiting atomically smooth surfaces with a root mean square (RMS) roughness of just 0.75 nm. The laser-induced β-Sn demonstrates superconductivity with a critical temperature of 3.7 K and a Ginzburg-Landau coherence length (ξ_GL) of 68.2 nm. Notably, β-Sn nanowires patterned through this method exhibit a pronounced superconducting diode effect, reaching a maximum rectification ratio (η) of 10.8%. These findings establish laser irradiation as a versatile, non-destructive, and scalable approach for fabricating high-quality α-Sn/β-Sn heterostructures, offering a promising route toward next-generation superconducting quantum devices.