Superconducting Fluxon Pumps and Lenses

TL;DR

This paper investigates a novel 2D superconducting fluxon pump that uses AC rectification and asymmetrical channels to generate directed fluxon motion, with potential applications in fluxon optics and superconducting devices.

Contribution

It introduces a new 2D geometric fluxon pump that differs from 1D ratchets, demonstrating AC rectification and fluxon lensing effects in superconductors.

Findings

Thermal fluctuations enable diode-like fluxon rectification.

Asymmetrical channel walls induce net DC fluxon motion.

Potential applications in SQUID magnetometers and fluxon optics.

Abstract

We study stochastic transport of fluxons in superconductors by alternating current (AC) rectification. Our simulated system provides a fluxon pump, "lens", or fluxon "rectifier" because the applied electrical AC is transformed into a net DC motion of fluxons. Thermal fluctuations and the asymmetry of the ratchet channel walls induce this "diode" effect, which can have important applications in devices, like SQUID magnetometers, and for fluxon optics, including convex and concave fluxon lenses. Certain features are unique to this novel two-dimensional (2D) geometric pump, and different from the previously studied 1D ratchets.