A study of a superconducting magnetic levitation system for an absolute determination of the magnetic flux quantum

A study of the equilibrium positions of a superconducting magnetic lévitation system which substitutes an electromagnetic energy for a mechanical energy is in progress for the absolute determination of the magnetic flux quantum Φ0. The study on a preliminary system at ppm-level resolution has been done and the reproducibility of the trajectory turned out to be of the order of 10 ppm. The problems of the present system and ideas for the next system at the sub-ppm level are discussed.