Unconventional Resistivity Scaling in Topological Semimetal CoSi

Abstract

Nontrivial band topologies in semimetals lead to robust surface states that can contribute dominantly to the total conduction. This may result in reduced resistivity with decreasing feature size contrary to conventional metals, which may highly impact the semiconductor industry. Here we study the resistivity scaling of a representative topological semimetal CoSi using realistic band structures and Green's function methods. We show that there exists a critical thickness d_c dividing different scaling trends. Above d_c, when the defect density is low such that surface conduction dominates, resistivity reduces with decreasing thickness; when the defect density is high such that bulk conduction dominates, resistivity increases in as conventional metals. Below d_c, the persistent remnants of the surface states give rise to decreasing resistivity down to the ultrathin limit, unlike in topological insulators. The observed CoSi scaling can apply to broad classes of topological semimetals, providing guidelines for materials screening and engineering. Our study shows that topological semimetals bear the potential of overcoming the resistivity scaling challenges in back-end-of-line interconnect applications.

References in corpus (5)

• Multiple types of topological fermions in transition metal silicides
• Large Fermi Arcs in Unconventional Weyl Semimetal RhSi
• Discovery of topological chiral crystals with helicoid arc states
• Topological Semimetal Nanostructures: From Properties to Topotronics
• Topological Semimetals for Scaled Back-End-Of-Line Interconnect Beyond Cu

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• Nonlinear longitudinal current of band-geometric origin in wires of finite thickness
• Accelerated Discovery of Topological Conductors for Nanoscale Interconnects