Evidence of universality in the dynamical response of micromechanical diamond resonators at millikelvin temperatures

Abstract

We report kelvin to millikelvin-temperature measurements of dissipation and frequency shift in megahertz-range resonators fabricated from ultra-nanocrystalline diamond. Frequency shift $\delta f/f_0$ and dissipation $Q^{-1}$ demonstrate temperature dependence in the millikelvin range similar to that predicted by the glass model of tunneling two level systems. The logarithmic temperature dependence of $\delta f/f_0$ is in good agreement with such models, which include phonon relaxation and phonon resonant absorption. Dissipation shows a weak power law, $Q^{-1}\propto T^{1/3}$, followed by saturation at low temperature. A comparison of both the scaled frequency shift and dissipation in equivalent micromechanical structures made of single-crystal silicon and gallium arsenide indicates universality in the dynamical response.

5 pages, two figures, one table, two-column format. Related papers can be found at http://nano.bu.edu/

References in corpus (3)

• Quantum Friction in Nanomechanical Oscillators at Millikelvin Temperatures
• Scaling of dissipation in megahertz-range micromechanical diamond oscillators
• Dissipation due to two-level systems in nano-mechanical devices

Cited by in corpus (3)

• A macroscopic object passively cooled into its quantum ground state of motion: beyond single-mode cooling
• Nanomechanical damping via electron-assisted relaxation of two-level systems
• Soft-clamped silicon nitride string resonators at millikelvin temperatures