Ultralow Resistivity of the Graphite/Au van der Waals Heterostructure in the Structural Superlubric State

Abstract

Structural superlubricity, a state of zero wear and ultralow friction between two sliding solid contact surfaces, offers transformative potential for NEMS/MEMS switches, relays, logic devices, and sensors. Ultralow resistivity in two-dimensional (2D)/three-dimensional (3D) van der Waals heterostructures is critical for most applications. Using high-vacuum thermal evaporation of Au, we fabricate defect-free single-crystal graphite/Au van der Waals heterostructures in the SSL state, achieving a record-low resistivity of 2.542 × 10 −12 Ω m 2 , which is 6 times lower than that of prior reports. The resistance remains stable under varying loads and speeds, attributed to the all-atom contact and defect-free single-crystal graphite. Thermal evaporation of Au preserves the single-crystal graphite 2D lattice, enabling lower resistivity. The 2D/3D SSL heterostructure is simpler, more stable, and broadly more applicable than 2D/2D systems. It establishes the electrical foundation for applying superlubric technology in micro-nano devices and provides a platform for studying fundamental behaviors at 2D/3D sliding interfaces, including electron friction, phonon dissipation, and electron transfer.