Josephson Plasma Resonances and Optical Properties in High-T_c Superconductors with Alternating Junction Parameters

Abstract

We investigate the phase dynamics in an intrinsic Josephson-junction array with alternating junction parameters, taking account of both capacitive and inductive couplings between junctions. The dynamical equations for the phase differences are derived in both longitudinal and transverse configurations. In the transverse configuration we derive the explicit expression for the electromagnetic field excited by incident light on the bc-plane with the polarization E || c-axis under the correct boundary conditions. This calculation provides complete description for the transverse-optical Josephson plasma predicted by van der Marel and Tsvetkov. It is also shown that the formula for the reflection spectrum derived by van der Marel and Tsvetkov in the bc-plane of high-T_c superconductors with alternating block layers is valid in the strong inductive-coupling limit.