The design of a very high-Q superconductor electromechanical clock

Abstract

We discuss theoretically the properties of an electromechanical oscillator whose operation is based upon the cyclic, quasi-conservative conversion between gravitational potential, kinetic, and magnetic energies. The system consists of a strong-pinning type-II superconductor square loop subjected to a constant external force and to magnetic fields. The loop oscillates in the upright position at a frequency that can be tuned in the range 10-1000 Hz, and has induced in it a rectified electrical current. The emphasis of this paper is on the evaluation of the major remaining source of losses in the oscillations. We argue that such losses should be associated with the viscous vibration of pinned flux lines in the superconductor Nb-Ti wire, provided the oscillator is kept close to zero Kelvin, under high-vacuum, and the magnetic field is sufficiently uniform. We discuss how other different sources of loss would become negligible for such operational conditions, so that a very high quality factor Q exceeding 10^(10) might in principle be reached by the oscillator. The prospective utilization of such oscillator as a low-frequency high-Q clock is analyzed.Since publication the ideas in this paper have been explored both by the author and elsewhere, in applications covering Metrology, quantum systems, and gravimetry.