Superconducting Plasma Excitation at Microwave Frequencies in Parallel Magnetic Fields in $\mathbf{B}{\mathbf{i}}_2\mathbf{S}{\mathbf{r}}_2\mathbf{CaC}{\mathbf{u}}_2{\mathbf{O}}_{8+\delta }$

K. Kadowaki, T. Wada, I. Kakeya

Josephson plasma resonance has been studied in a wide microwave frequency range between 10 and 52 GHz in a magnetic field parallel to the $ab$-plane in under-doped $\BI$. Above abo…