Electronic friction and tuning on atomically thin MoS2

Abstract

Friction is an energy dissipation process. However, the electronic contribution to energy dissipation channels remains elusive during the sliding friction process. The friction and dissipation on atomically thin MoS2 with semiconductive characteristics are studied and tuned by the gate-modulated carrier concentration. The electronic contribution to energy dissipation of friction on atomically thin MoS2 was confirmed and regulated through tuning the strength of the electron-phonon coupling. The electron-phonon coupling can be strengthened and depressed to increase and decrease friction by the gate-modulation of the carrier concentration. The fitting of the friction on atomically thin MoS2 and carrier concentration is approximately linear which is in accordance with Langevin equation induced friction. Then the active, dynamical, and repeated tuning of friction on atomically thin MoS2 with semiconductive properties is achieved by the active modulation of carrier concentration with gate voltage. These observations help us to understand the electronic friction in essence, provide a utility approach to tune the friction intelligently on atomically thin two-dimensional materials with semiconductive properties and achieve superlubric properties for the application in various micro-and nanoelectromechanical systems.