Strained crystalline nanomechanical resonators with quality factors above 10 billion

In strained mechanical resonators, the concurrence of tensile stress and geometric nonlinearity dramatically reduces dissipation. This phenomenon, called dissipation dilution, is employed in mirror suspensions gravitational-wave interferometers at nanoscale, where soft clamping strain engineering have allowed extremely high quality factors. However, these techniques so far been applied only to amorphous materials, specifically Si3N4. Crystalline materials exhibit substantially lower intrinsic damping cryogenic temperatures. Applying dilution crystalline could, therefore, enable low loss nanomechanical as they combine internal friction, yield strength. potential has not yet fully exploited. Here we demonstrate that single-crystal silicon—a material developed for high-mobility transistors—can be used realize resonators with ultralow We fabricate silicon nanostrings aspect ratios supporting megahertz modes factors exceeding 1010 7 K, a tenfold improvement over values reported estimate thermal-noise-limited force sensitivity (5 ± 2) × 10–20 N Hz–1/2 K—approaching carbon nanotubes—and heating rate 60 quanta per second. The mass our make them particularly promising quantum sensing transduction. Soft but this method limited materials. When silicon, it enables beyond ten billion.