Synthesis and characterization of PtPb₄ nanowires

Nanostructuring is an attractive approach for studying how reduced dimensionality, topological surface states, and quantum confinement influence the electronic properties of quantum materials. In this work, we investigated the synthesis and properties of nanowires of the square-net metal PtPb₄, a topological nodal line semimetal exhibiting both nontrivial band topology and superconductivity. Using thermomechanical nanomolding – a novel synthesis technique for making intermetallic nanowires– we successfully extruded single-crystalline PtPb₄ nanowires from bulk PtPb₄ single crystals, with diameters ranging from 40 to 200 nm and lengths up to ~ 15 microns. Using standard e-beam lithography, we fabricated nanowire devices for transport measurements, and observed the suppression of superconductivity, as well as signatures of weak antilocalization and universal conductance fluctuations in ~90-nm wide nanowires. In addition, we examined the dimensionality scaling of their resistivities, and suggest synthesis and measurement strategies for further investigating the topological properties and possible superconductivity of PtPb₄ nanowires.