Delta-Interference of Two Friedel Resonances

TL;DR

This paper investigates how two Friedel resonances interfere when coupled to a continuum, revealing conditions under which one resonance becomes delta-like, which could impact various physical systems involving resonant interactions.

Contribution

It introduces the concept of interference between two Friedel resonances and demonstrates how to tune one resonance to become delta-like through effective coupling control.

Findings

Two Friedel resonances interfere when coupled to a continuum.

Under identical conditions, two effective resonances emerge.

One resonance can be tuned to have zero effective coupling, becoming delta-like.

Abstract

When a single resonator is coupled to a continuous spectrum one obtains a resonance of finite half-width. Such a resonance is known in many fields of physics. The Friedel resonance is an example where a d-impurity is dissolved in a simple metal. If two resonators are coupled to the continuous spectrum the resonances interfere. For identical coupling and frequencies one obtains two effective resonances. The effective coupling of one of them to the continuum can be tuned to zero yielding a delta-like resonance.