Fig. 4: Quality factor validation.
From: Centimeter-scale nanomechanical resonators with low dissipation
a Optical picture of the optimized 3 cm nanoresonators. For illustration purposes, the picture is scaled along the vertical direction as indicated by the two scale bars. b Mode shape of the eigenmode predicted to have high quality factor extracted from finite elements analysis. c Balanced homodyne optical interferometer built to experimentally measure the 3 cm nanoresonators. The nanoresonator is placed inside an ultra-high vacuum (UHV) chamber and mechanically excited by a piezoelectric actuator. Its motion is detected by an infrared laser via a lensed fiber. VOA variable optical attenuator, FPC fiber polarization controller, PID proportional integral derivative controller, Φ fiber stretcher. d Ringdown trace of optimized nanoresonator excited at 214 kHz. The black solid line indicates the linear fitting corresponding to an extracted quality factor of 6.6 billion at room temperature. e Thermomechanical noise spectrum.
