Novel Microwave Absorption Due to Strong Coupling between Josephson Plasma and the Josephson Vortex Array in Bi${}_2$Sr${}_2$CaCu${}_2$O${}_{8+\delta }$

I. Kakeya, T. Wada, K. Kadowaki

We have investigated the Josephson plasma excitations in magnetic fields parallel to the $ab$-plane in Bi${}_2$Sr${}_2$CaCu${}_2$O${}_{8+\delta }$ single crystals in a wide microwave frequency r…