SOME EXOTIC PHENOMENA RELATED TO VORTICES IN HIGH-T-C AND HEAVY-FERMION SUPERCONDUCTORS

Discussions are given on two topics. The superconducting current along the c-axis of a cuprate superconductor flows through the Josephson co upling between the CuO2 layers. The superconducting current is coupled with the electromagnetic field, generating a Josephson plasma with a low frequency. The Josephson plasma strongly interacts with the vortic es, and thus the plasma frequency is strongly dependent on magnetic fi eld and temperature. Since the interaction is strong enough, the plasm a will be excited by the vortex flow. The other topic concerns a new s tate appearing in a high magnetic field near H-c2 of heavy fermion and intermediate valence superconductors, such as UPd2Al3 and CeRu2. It i s predicted that the order parameter in the state is spatially modulat ed, and planar nodes of the order parameter are periodically aligned p erpendicular to the vortices. The nature of the state will be discusse d in relation to anomalous properties of the magnetization, the crysta l dilation, and other physical quantities observed in the vortex state of the compounds.