Fig. 3: Results overview.
From: Ultra-coherent nanomechanical resonators based on inverse design
a Overview of the measured frequencies and quality factors across all designs and thicknesses together with selected microscope images. Solid lines correspond to theory fitted to the measured frequencies and best attained quality factors. Dotted and dashed lines are associated with the phonon tunneling and intrinsic loss contributions, respectively. For some designs, the theory curves for the phonon tunneling loss is not visible on the plots. b Quality factor plotted against frequency for the five best samples for each design. The shaded area marks the parameter regime in which the resonator may undergo quantum coherent oscillations at room temperature. The inset is the nominal trampoline design fabricated in this work and used as a reference13. The large spread in the Q factors is due to the uncontrollable coupling of the fundamental mode to the substrate mode. In the Qf plot, we only include measurements of membranes for which the Q factor was above 107 but all measurement data are included in the plots for the frequency and Q factor.
