Intrinsic dissipation due to mode coupling in two-dimensional-material resonators revealed through a multiscale approach

While there has been tremendous progress in realizing high frequency, tunable, stable, atomically thin microresonators from individual two-dimensional (2D) materials and their combinations, their poor mechanical resonance quality at room temperature is still an open area of research. Taking a multiscale modeling approach and graphene as a representative 2D system, we show that intrinsic dissipation due to flexural mode coupling can explain the room temperature behavior. The inverse quality factor Q-1, a nondimensional measure of dissipation, solely due to the coupling with nanometer wavelength flexural modes in the structure is found to be nonlinear in the vibration amplitude, and also dependent on the resonator size, strain, and temperature. At lower amplitudes and submicron to micron sizes, however, Q-1 mediated by coupling with the submicro-to micrometer wavelength flexural modes dominates. This Q-1 is amplitude independent, and bears a similar implicit dependence on the temperature (T) and inverse strain (1/I), suggesting that T/I is a better metric to characterize the dissipation.