Coherent emission from disordered arrays of driven Josephson vortices
  We propose a mechanism of coherent emission from driven vortices in stacked intrinsic Josephson junctions. In contrast to super-radiance, which occurs only for highly ordered vortex lattices, we predict resonant radiation emission from weakly correlated vortex arrays. Our analytical results for the THz wave intensity, resonance frequencies, and the dependence of THz emission power on dissipation are in good agreement with the ones obtained by recent simulations. 
Fabio Marchesoni, Sergey Savel'ev, Masashi Tachiki, Franco Nori
cond-mat.supr-con