By Ada
Researchers at Cornell University have demonstrated that nanowires made from niobium arsenide (NbAs), a topological quantum material, become better conductors as they shrink, the opposite of copper, which degrades at nanoscale, opening the door to a new class of chip interconnects.
The challenge facing chip designers is fundamental: as transistors shrink, the copper wires that connect them also get thinner, and copper’s electrical resistance rises sharply due to increased surface scattering of electrons. This resistance limits both performance and energy efficiency.
NbAs is a topological semimetal, a class of material where electrons flow primarily along the surface and scatter far less than electrons traveling through the bulk. “Electrons that are flowing on the surface of the material travel really fast, and they do not scatter off as easily as electrons in the bulk,” said Judy Cha, the study’s senior author. As NbAs wires get thinner, the surface effects dominate, and conductivity actually improves.
The team fabricated single-crystal NbAs nanowires using a technique called thermomechanical nanomolding, in which bulk NbAs is pressed into a porous aluminum oxide mold at high temperature. Removing the mold leaves high-quality wires with diameters as small as 10 nanometers. Cha compared the process to making pasta, swapping the mold changes the wire’s shape.
Key advantages of the material include room-temperature operation, meaning no cryogenic cooling is required; compatibility with standard silicon wafer processing; and a fabrication method that the team says can produce one new material candidate per month, compared to one or two per year with traditional methods.
The research was published in the journal Science (DOI: 10.1126/science.adx3027) and positions niobium arsenide as a viable candidate to replace copper in the interconnects of next-generation microchips, potentially extending the roadmap for chip miniaturization.
Sources: US scientists find new material that outperforms copper in tiny computer chips (Interesting Engineering, Jul 17); Science journal publication (Science, 2026)