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.
@article{arxiv.0907.5484,
title = {Field cooling memory effect in Bi2212 and Bi2223 single crystals},
author = {D. Shaltiel and H-A. Krug von Nidda and B. Rosenstein and B. Ya. Shapiro and M. Golosovsky. and I. Shapiro and A. Loidl and B. Bogoslavsky and T. Fujii and T. Watanabe and T. Tamegai},
journal= {arXiv preprint arXiv:0907.5484},
year = {2015}
}