28 research outputs found
Field cooling memory effect in Bi2212 and Bi2223 single crystals
A memory effect in the Josephson vortex system created by magnetic field in
the highly anisotropic superconductors Bi2212 and Bi2223 is demonstrated using
microwave power absorption. This surprising effect appears despite a very low
viscosity of Josephson vortices compared to Abrikosov vortices. The
superconductor is field cooled in DC magnetic field H_{m} oriented parallel to
the CuO planes through the critical temperature T_{c} down to 4K, with
subsequent reduction of the field to zero and again above H_{m}. Large
microwave power absorption signal is observed at a magnetic field just above
the cooling field clearly indicating a memory effect. The dependence of the
signal on deviation of magnetic field from H_{m} is the same for a wide range
of H_{m} from 0.15T to 1.7T