Control of quantum interference in molecular junctions: Understanding the origin of Fano and anti- resonances

TL;DR

This paper explores how Fano and anti-resonances arise in molecular junction conductance, using a simplified model and validating findings with quantum transport calculations on realistic T-shaped molecular systems.

Contribution

It introduces a graphical parabolic diagram to visualize electronic parameters influencing Fano and anti-resonances in molecular junctions.

Findings

Graphical diagram effectively visualizes electronic regimes.

Conditions for Fano and anti-resonances are identified.

Model validated with quantum transport calculations.

Abstract

We investigate within a coarse-grained model the conditions leading to the appearance of Fano resonances or anti-resonances in the conductance spectrum of a generic molecular junction with a side group (T-junction). By introducing a simple graphical representation (parabolic diagram), we can easily visualize the relation between the different electronic parameters determining the regimes where Fano resonances or anti-resonances in the low-energy conductance spectrum can be expected. The results obtained within the coarse-grained model are validated using density-functional based quantum transport calculations in realistic T-shaped molecular junctions.