Intermodal Coupling Induced Nonlinear Damping in Molybdenum Disulfide (MoS2) Resonator

In this work, we provide experimental evidence to support the theoretical understanding of the microscopic origin of nonlinear damping in molybdenum disulfide (MoS2) resonator mediated through intermodal coupling. In atomically thin two-dimensional membranes, the effect of intermodal coupling on energy dissipation cannot be ignored since the vibrational modes are intrinsically coupled through membrane strain. The origin of nonlinear damping in Mos2 resonator due to intermodal coupling (internal resonance) is observed in the linear regime with varying gate bias. We further confirm our hypothesis through observation of fundamental mode peak splitting arising due to strong intermodal coupling at higher actuation force (≈ 0.45nN).