Interaction between Josephson and pancake vortices investigated by the induced microwave dissipation by ac magnetic field technique

Abstract

In the "induced microwave dissipation by ac magnetic field" (IMDACMF) technique, only the motion of Josephson vortices (JV) but not of pancake vortices (PV) induces microwave dissipation. This unique property is used to investigate the interaction between JV and PV in the high anisotropy superconductor Bi2212 as a function of magnetic field and tilting angle away from the a-b plane. In general, pinning of JV by PV inhibits the motion of the JV and, thus, reduces the microwave dissipation. Almost no pinning of JV is obtained at low dc magnetic fields even at high-tilting angles. Strong pinning of JV due to their interaction with PV is observed at higher magnetic fields and at tilting angles between 50 degrees and 90 degrees. The technique enables to observe transitions from the JV state to the crossing lattice state, without and with interaction between JV and PV, and to the one-dimensional vortex chains. The results obtained by the present technique are compared to results of surface imaging techniques, which investigate the interaction between PV and JV probing the PV.