Tailored dissipation for directional transport in plasmonic ratchets

TL;DR

This paper demonstrates how tailored dissipation in plasmonic waveguides can enhance directional transport and reduce losses, using Floquet theory and experimental microscopy to reveal optimal regimes for efficient ratchet behavior.

Contribution

It introduces a novel approach of using time-periodic dissipation in plasmonic ratchets, combining theoretical Floquet analysis with experimental validation to optimize directional transport.

Findings

Increased local dissipation improves rectified transport.

Optimal driving frequencies and loss rates enable efficient transport.

Sharp transitions and exceptional points characterize the behavior.

Abstract

We present a joint experimental and theoretical study of a ratchet implemented in arra ys of evanescently coupled plasmonic waveguides with tailored losses. In this setup the time-periodic dissipation is the only active mechanism and notably, we find better rectified transport and lower losses in the transmitted signal with increased local dissipation. Using Floquet theory, we uncover a driving regime that allows efficient directional tr ansport for suitable driving frequencies and loss rates, which are linked to linear qu asienergy bands with minimal losses. These regions are separated from non-resonant beh avior by sharp transitions with characteristic exceptional points in the spectrum. Direct experimental observation of the Floquet-dissipative ratchet effect using a comb ination of real- and Fourier-space leakage radiation microscopy is provided.