Controlling Fano Profiles via Conical Intersections

TL;DR

This paper introduces an analytical model for Fano resonances in two-channel systems, revealing how conical intersections of background phase shifts enable control over Fano lineshapes, with applications demonstrated in quantum billiards.

Contribution

It presents a novel analytical framework that decomposes the Fano lineshape parameter into background and interaction parts, highlighting the role of conical intersections in controlling resonance profiles.

Findings

Decomposition of q into background and interaction contributions.

Identification of conical intersections affecting phase shifts.

Demonstration of Fano profile control in quantum billiards.

Abstract

An ab initio analytical model for Fano resonances in two-channel systems is presented. We find that the lineshape parameter q factors into a background contribution q_b that depends only on the uncoupled channels and an interaction contribution q_i that is affected by the coupling between the channels, revealing how the overall lineshape parameter q may be controlled. In particular, we show how conical intersections of the background phase shifts have an important role in the interplay between q_b and q_i. Finally, control of Fano transmission profiles through q_b and q_i is demonstrated for quantum billiards.