In-gap corner states in core-shell polygonal quantum rings

TL;DR

This paper investigates how Coulomb interactions in polygonal quantum rings lead to in-gap corner states, revealing new localized electron pair states and conditions for their optical excitation.

Contribution

It demonstrates the formation of in-gap corner-localized states due to Coulomb repulsion, a novel phenomenon in polygonal quantum rings.

Findings

Coulomb repulsion enables in-gap corner states.

Corner states involve electron pairs or clusters.

Conditions for optical excitation of these states are identified.

Abstract

We study Coulomb interacting electrons confined in polygonal quantum rings. We focus on the interplay of localization at the polygon corners and Coulomb repulsion. Remarkably, the Coulomb repulsion allows the formation of in-gap states, i.e. corner-localized states of electron pairs or clusters shifted to energies that were forbidden for uncoupled electrons, but below the energies of side-localized states. We also specify conditions allowing optical excitation of those states.