High efficiency deterministic Josephson Vortex Ratchet

TL;DR

This paper experimentally studies a Josephson vortex ratchet with high efficiency, demonstrating quantized rectified voltage, chaos, and voltage reversal under various driving conditions in an asymmetric potential.

Contribution

It introduces a highly efficient Josephson vortex ratchet with a novel asymmetric potential and explores its behavior under different driving forces, including quantization and chaos phenomena.

Findings

Efficiency up to 91% in fluxon rectification

Quantized rectified voltage under high-frequency drive

Observation of chaos and voltage reversal at high frequencies

Abstract

We investigate experimentally a Josephson vortex ratchet -- a fluxon in an asymmetric periodic potential driven by a deterministic force with zero time average. The highly asymmetric periodic potential is created in an underdamped annular long Josephson junction by means of a current injector providing efficiency of the device up to 91%. We measured the ratchet effect for driving forces with different spectral content. For monochromatic high-frequency drive the rectified voltage becomes quantized. At high driving frequencies we also observe chaos, sub-harmonic dynamics and voltage reversal due to the inertial mass of a fluxon.