Surface-dominant electrical transport in Weyl semimetal NbAs nanowires

Topological semimetals possess topologically protected non-trivial surface states, which are predicted to mitigate electron backscattering. Due to the absence of backscattering on the surface, certain topological semimetals can exhibit decreasing resistivity with decreasing size, enabling further downscaling of integrated circuits. Niobium arsenide (NbAs) is a type-I Weyl semimetal with 12 pairs of Weyl nodes located near the Fermi level. Surface projections of these nodes are connected by long Fermi arcs, resulting in a high density of surface states. Although theoretical calculations on model NbAs slabs predict a significant surface contribution to the electrical conduction at the nanoscale, experimental work has been limited due to a lack of high-quality synthesis methods that produce nanostructures with controlled morphology and dimensions. In this work, we fabricate single-crystalline NbAs nanowires with sub-100 nm diameters using thermomechanical nanomolding. These NbAs nanowires exhibit exotic resistivity scaling behavior, which could be attributed to the surface-dominant conduction. To further investigate the electrical properties of NbAs nanowires, magneto-transport measurements at low temperature are compared with their bulk counterparts.