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arXiv · 0803.1669

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

Matthias Imboden·Pritiraj Mohanty
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Abstract

We report kelvin to millikelvin-temperature measurements of dissipation and frequency shift in megahertz-range resonators fabricated from ultra-nanocrystalline diamond. Frequency shift $δf/f_0$ 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 $δf/ f_0$ 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.

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Matthias Imboden, Pritiraj Mohanty. 2009-03-11. Evidence of universality in the dynamical response of micromechanical diamond resonators at millikelvin temperatures. https://doi.org/10.1103/physrevb.79.125424

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