Josephson vortex lattices as scatterers of terahertz radiation: Giant magneto-optical effect and Doppler effect using terahertz tunable photonic crystals

摘要

The Josephson vortex (JV) lattice generated by the in-plane magnetic field H_(ab) is a periodic array that scatters Josephson plasma waves (JPWs) in layered superconductors. This produces a photonic band gap structure, i.e. terahertz (THz) photonic crystal, with easily tunable forbidden zones, or gaps, controlled either by the in-plane magnetic field or the transverse transport current J_⊥ flowing across the superconducting layers. A giant magneto-optical effect, that is a strong dependence of the reflection and transmission coefficients on the applied in-plane magnetic field H_(ab), is predicted. A relatively small change of H_(ab) can switch the sample from fully transparent to fully reflective within given frequency windows. Thus, the material can change from a THz glass to a mirror by merely changing either H_(ab) or J_⊥. The described effects might be useful for development switchable "glass/mirrors" THz filters tuned by either H_(ab) or J_⊥.