Fano resonances with discrete breathers

TL;DR

This paper investigates how discrete breathers affect wave scattering, revealing Fano resonances that cause total reflection and resonant transmission, with implications for electronic transport in mesoscopic systems.

Contribution

It provides a theoretical framework for understanding wave scattering by discrete breathers, including analytical results and extensions to various oscillator chains.

Findings

Total reflection occurs due to Fano resonance with localized states.

Analytical frequency dependence of transmission coefficient is derived.

The effect is relevant for electronic transport spectroscopy.

Abstract

A theoretical study of linear wave scattering by time-periodic spatially localized excitations (discrete breathers (DB)) is presented. We obtain that the wave propagation is strongly influenced by a local coupling between an open and closed channels generated by the DB. A peculiar effect of total reflection occurs due to a Fano resonance when a localized state originating from closed channels resonates with the open channel. For the discrete nonlinear Schroedinger chain we provide with an analytical result for the frequency dependence of the transmission coefficient, including the possibility of resonant reflection. We extend the analysis to chains of weakly coupled anharmonic oscillators and discuss the relevance of the effect for electronic transport spectroscopy of mesoscopic systems.