Electromagnetic radiation from vortex flow in type-II superconductors

TL;DR

This paper demonstrates that moving vortex lattices in type-II superconductors emit electromagnetic radiation at harmonics of the washboard frequency, which can be utilized for terahertz generation and vortex lattice characterization.

Contribution

It introduces the phenomenon of vortex lattice radiation at harmonics of the washboard frequency and explores its potential applications.

Findings

Vortex lattice radiation extends up to the superconducting gap.

Radiation power depends on vortex velocity and lattice parameters.

Potential for terahertz source development.

Abstract

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, $\Delta/\hbar$. 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 generation of terahertz radiation and for characterization of moving vortex lattices.