Novel electromagnetic effects in high-temperature superconductors

Abstract

We report the first observations at liquid-nitrogen temperatures of parametric inductance behavior, signal up-conversion, and the nondestructive read-out of persistent supercurrent states in a superconductor. These observations have been made using a toroidal transformer with a core of the high-temperature superconductor YBa2Cu3O6.8. The effects arise from the field-dependent behavior of the magnetic susceptibility of this superconductor.