Fig. 3: Viscoelastic dissipation dilution.
From: High-quality-factor viscoelastic nanomechanical resonators from moiré superlattices
a Quality factors Q corresponding to Fig. 2c for both forward and backward sweeps. b Q extracted from the mechanical response spectra and as a function of Vdc for drum 1 (D = 6 μm), drum 2 (D = 8 μm) and drum 3 (D = 12 μm), respectively. The dashed arrows denote the Q jumps revealed in drum 3. The solid lines in (a, b) are linear fits to the experimental data (see Supplementary section S2.2). c Top panel: the extended Kelvin-Voigt model, i.e., the intrinsic friction dashpot ηi is added in parallel to the model that has been introduced in Fig. 2b, but here ηs is explicitly replaced by a “lossless" viscoelastic spring ks. Bottom panel: a cartoon of the Prandtl-Tomlison model, where the tip slides on top of a one-dimensional chain of springs, which moves on top of a fixed potential. d The Vdc-dependent Q extracted from the ring-down measurements (Ring.) and fitting of the mechanical responses (M.R.) in drum 11 (D = 12 μm) of Device E. Error bars in the traces of Ring. and M.R. are extracted from the fits of energy decay and mechanical responses, respectively. Note that the ringdown trace has been shifted up by 50 for direct comparison (see Methods). e Energy decay traces (in log scale) at different Vdc in drum 11 (D = 12 μm) of Device E (see Methods).
