Revisit to terahertz wave emission with motions of Josephson vortices

By use of a recently developed multi-scale simulation method, we re-investigate terahertz wave emission with motions of Josephson vortices, as a possible mechanism for enhancing the emitted power. Results show that there appears a strong wave emission around the n = 2 cavity mode (one-wavelength mode), when motions of vortices and cavity modes are resonate.

► Magnetic field H-dependence of the terahertz wave emission is investigated.
► There are strong emissions in the cavity modes of the π− and 2π-mode.
► The phase state of the π-mode is π-kink like, while that of 2π-mode changes with H.
► Near one flux per junction, a coherent in-phase vortex lattice state is realized.
► A strong emission is induced by synchronization of the vortex motion and cavity mode.