This letter describes a very simple electromechanical oscillator, consisting of a strong-pinning Nb-Ti superconductor loop subjected to static magnetic fields. A detailed calculation of the losses occurring during its low-frequency oscillations is carried out. The conclusion is that the quality factor for such oscillator might reach the 10^10-10^11 range, something comparable only to the best optical microcavities. Such device might permit the measurement of variations in static forces with the same precision a superconducting quantum interference device (SQUID) measures variations of magnetic field, providing a new tool for probing minute variations of the gravitational field. for instance.
@article{arxiv.cond-mat/0510767,
title = {A low-frequency superconductor oscillator with a 10^10-quality factor},
author = {O. F. Schilling},
journal= {arXiv preprint arXiv:cond-mat/0510767},
year = {2007}
}