Stopping of levitation force relaxation in superconductors: the flux-locking effect

Stopping of levitation force relaxation in superconductors under conditions of flux creep was studied experimentally. This effect appears when the flux profile is modulated in the near-surface layer of a superconductor. It was assumed that levitation was stabilized thanks to locking of the magnetic flux and internal magnetic relaxation. During this relaxation, the flux was redistributed in a sample, but the full flux and the average magnetization of the sample remained unchanged. A parameter characterizing the modulation depth was introduced. This parameter allows calculating the time during which the levitation force is constant.