We show that a moving vortex lattice, as it comes to a crystal edge, radiates into a free space the harmonics of the washboard frequency, ${\omega }_0=2\pi v/a$, up to a superconducting gap, $\Delta /\hslash$. Here $v$ is the velocity of the vortex lattice and $a$ is the intervortex spacing. We compute radiation power and show that this effect can be used for the generation of terahertz radiation and for characterization of moving vortex lattices.

• Received 14 April 2006

DOI:https://doi.org/10.1103/PhysRevLett.97.197002