Suppression of Magnetic Force Relaxation in a Magnet-High $T_{c}$ Superconductor System

We have measured that the levitation forces relax at the different order equilibrium positions of a bulk YBaCuO superconductor. In a given symmetrical levitation system, high order equilibrium positions can be obtained by increasing the number of the reversal movements of the magnet; the higher order equilibrium position, the lower the relaxation of the levitation force. This method is confirmed experimentally and theoretically. For the unsymmetrical levitation system, one movement mode of the magnet and/or superconductor can reduce the relaxations of the levitation force and guidance force synchronously while the quantities of the levitation force and guidance force are depressed little.