Hysteresis of the dynamical magnetic permeability of a YBa 2Cu 3O 7−δ single crystal

Abstract

The YBa 2Cu 3O 7−δ single crystal dynamical magnetic permeability μ versus magnetic field dependences are measured for the first time. Two contributions to μ are revealed, one of which rises linearly with the AC field amplitude H 1 while the other does not depend on H 1 and displays hysteretic behavior in a cycling DC field. Calculations suggest that the latter contribution comes from the AC field-induced oscillations of the flux lines around their equilibrium positions. Theoretical estimations show that the possible cause underlying the hysteresis is a local reversible shift of the vortex lattice when changing the DC field scan direction.