The mechanical resonance properties of a micro-electro-mechanical oscillator with a gap of 1.25 μm was studied in superfluid 3He-B at various pressures. The oscillator was driven in the linear damping regime where the damping coefficient is independent of the oscillator velocity. The quality factor of the oscillator remains low (Q≈80) down to 0.1 Tc, 4 orders of magnitude less than the intrinsic quality factor measured in vacuum at 4 K. In addition to the Boltzmann temperature dependent contribution to the damping, a damping proportional to temperature was found to dominate at low temperatures. We propose a multiple scattering mechanism of the surface Andreev bound states to be a possible cause for the anomalous damping.
@article{arxiv.1606.04483,
title = {Anomalous Damping of a Micro-electro-mechanical Oscillator in Superfluid $^3$He-B},
author = {P. Zheng and W. G. Jiang and C. S. Barquist and Y. Lee and H. B. Chan},
journal= {arXiv preprint arXiv:1606.04483},
year = {2016}
}