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Quantum Friction of Micromechanical Resonators at Low Temperatures

Kang-Hun Ahn·Pritiraj Mohanty
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Abstract

Dissipation of micro- and nano-scale mechanical structures is dominated by quantum-mechanical tunneling of two-level defects intrinsically present in the system. We find that at high frequencies--usually, for smaller, micron-scale structures--a novel mechanism of phonon pumping of two-level defects gives rise to weakly temperature-dependent internal friction, $Q^{-1}$, concomitant to the effects observed in recent experiments. Due to their size, comparable to or shorter than the emitted phonon wavelength, these structures suffer from superradiance-enhanced dissipation by the collective relaxation of a large number of two-level defects contained within the wavelength.

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Kang-Hun Ahn, Pritiraj Mohanty. 2003-01-15. Quantum Friction of Micromechanical Resonators at Low Temperatures. https://doi.org/10.1103/physrevlett.90.085504

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