Dynamic tuning of terahertz atomic lattice vibration via cross-scale mode coupling to nanomechanical resonance in WSe2 membranes

Dynamic tuning of terahertz atomic lattice vibration via cross-scale mode coupling to nanomechanical resonance in WSe2 membranes

Blog Article

Abstract Nanoelectromechanical systems (NEMS) based on atomically-thin tungsten diselenide (WSe2), benefiting from the excellent material properties and the mechanical degree of freedom, offer an ideal platform for studying and exploiting dynamic strain engineering and cross-scale vibration coupling in two-dimensional (2D) crystals.However, such opportunity has remained largely unexplored for WSe2 NEMS, impeding exploration of exquisite physical processes and realization of novel device functions.Here, we demonstrate dynamic coupling between Pre-Rolls atomic lattice vibration and nanomechanical resonances in few-layer WSe2 NEMS.Using a custom-built setup capable of simultaneously detecting Raman and motional signals, we accomplish cross-scale mode coupling between the THz crystal phonon and MHz structural vibration, achieving GHz frequency skateboards tuning in the atomic lattice modes with a dynamic gauge factor of 61.9, the best among all 2D crystals reported to date.

Our findings show that such 2D NEMS offer great promises for exploring cross-scale physics in atomically-thin semiconductors.