 
Summary: Journal of Superconductivity: Incorporating Novel Magnetism ( C 2006)
DOI: 10.1007/s1094800601765
Radiation from Flux Flow in Josephson Junction Structures
L. N. Bulaevskii1 and A. E. Koshelev2
We derive the radiation power from a single Josephson junction (JJ) and from layered
superconductors in the fluxflow regime. For JJ case, we formulate the boundary condi
tions for the electric and magnetic fields at the edges of the superconducting leads using
the Maxwell equations in the dielectric media and find dynamic boundary conditions for the
phase difference in JJ which account for the radiation. We derive the fraction of the power fed
into JJ transformed into the radiation. In a finitelength JJ this fraction is determined by the
dissipation inside JJ and it tends to unity as dissipation vanishes independently of mismatch of
the junction and dielectric media impedances. We formulate also the dynamic boundary con
ditions for the phase difference in intrinsic JJs in highly anisotropic layered superconductors
of the Bi2Sr2CaCu2O8 type at the boundary with free space. Using these boundary conditions,
we solve equations for the phase difference in the linear regime of Josephson oscillations for
rectangular and triangular lattices of Josephson vortices. In the case of rectangular lattice
for crystals with the thickness along the caxis much larger than the radiation wavelength,
we estimate the radiation power per unit length in the direction of magnetic field at the fre
quency 1 THz as N µW/cm for Tl2Ba2CaCu2O8 and 0.04 N µW/cm for Bi2Sr2CaCu2O8.
For crystals with thickness smaller than the radiation wavelength, we found that the radiation
