Fano Resonances in Quantum Transport with Vibrations

TL;DR

This paper develops a multichannel quantum scattering method to analyze how vibrational modes influence Fano resonances in quantum transport, revealing that vibrations can significantly alter transparency and reflectivity in various quantum systems.

Contribution

The authors introduce a novel multichannel scattering approach to incorporate vibrational degrees of freedom into quantum transport analysis, enabling more accurate modeling of vibrational effects.

Findings

Vibrations can turn opaque spectral regions transparent in quantum transport.

The formalism applies to molecular, atomic, and polymer-based quantum systems.

Vibrational modes profoundly affect Fano resonance features.

Abstract

Quantum mechanical scattering involving continuum states coupled to a scatterer with a discrete spectrum gives rise to Fano resonances. Here we consider scatterers that possess internal vibrational degrees of freedom in addition to discrete states. Entanglement between the scattered excitation and vibrational modes complicates analytical and numerical calculations considerably. For the example of one-dimensional scattering we develop a multichannel quantum scattering approach which can determine reflection and transmission probabilities in the presence of vibrations. Application to a linear chain coupled to a control unit containing vibrating sites shows that vibrational degrees of freedom can have a profound effect on quantum transport. For suitable parameters, spectral regions which are opaque in the static case can be rendered transparent when vibrations are included. The formalism is general enough to be applicable to a variety of platforms for quantum transport including molecular aggregates, cold atom chains, quantum-dot arrays and molecular wires based on conjugated polymers.