Probing the zero energy shell wave functions of triangular graphene quantum dots with broken sublattice symmetry using a localized impurity

TL;DR

This paper introduces a method to probe the wave functions of zero energy shells in triangular graphene quantum dots with broken sublattice symmetry using localized impurities, validated by theoretical and experimental comparisons.

Contribution

It presents a novel approach to analyze wave functions in graphene quantum dots with impurities, combining analytical, tight-binding, ab-initio, and experimental methods.

Findings

Impurity allows probing of wave functions at specific sites.

Predicted zero energy shell structure matches calculations and experiments.

Method applicable to various impurity configurations in graphene dots.

Abstract

We present here a method of probing the wave functions of a degenerate shell in a triangular graphene quantum dot, triangulene, using a localized substitutional impurity. We demonstrate its applicability to the example of aza-triangulenes. Using the analytical solution for degenerate states of an all-carbon triangulene as a basis for a triangulene containing a nitrogen impurity, we predict the structure of the zero energy shell in the presence of this impurity. We show that the impurity allows probing of the wave functions of a degenerate shell on a carbon site where it is located. We confirm our predictions by a comparison with the tight-binding and ab-initio calculation as well as with experiment.