Electronic friction and tuning on atomically thin MoS 2

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 MoS 2 with semiconductive characteristics are studied and tuned by the gate-modulated carrier concentration. The electronic contribution to energy dissipation of friction on atomically thin MoS 2 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 MoS 2 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 MoS 2 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.