Catching the Bound States in the Continuum of a Phantom Atom in Graphene

TL;DR

This paper theoretically investigates the formation of bound states in the continuum (BICs) in graphene with two collinear adatoms, revealing conditions for BICs related to Fano interference and Coulomb correlations.

Contribution

It introduces a novel configuration of adatoms in graphene that leads to BICs, highlighting the role of Fano interference and Coulomb interactions, which was not previously demonstrated.

Findings

BICs form due to Fano destructive interference in specific adatom configurations.

The local density of states shows a cubic energy dependence near Dirac points.

BICs are absent when adatoms are collinear with carbon atoms.

Abstract

We explore theoretically the formation of bound states in the continuum (BICs) in graphene hosting two collinear adatoms situated at different sides of the sheet and at the center of the hexagonal cell, where a phantom atom of a fictitious lattice emulates the six carbons of the cell. We verify that in this configuration the local density of states (LDOS) near the Dirac points exhibits two characteristic features: i) the cubic dependence on energy instead of the linear one for graphene as found in New J. Phys. 16, 013045 (2014) and ii) formation of BICs as aftermath of a Fano destructive interference assisted by the Coulomb correlations in the adatoms. For the geometry where adatoms are collinear to carbon atoms, we report absence of BICs.