Variational Scarring in Graphene Quantum Dots

TL;DR

This paper proposes that variational scarring, a recently theorized quantum phenomenon, can be observed in graphene quantum dots using scanning tunneling microscopy, bridging theory and experiment.

Contribution

It demonstrates the potential for experimental detection of variational scarring in graphene quantum dots with local perturbations, a phenomenon previously only observed numerically.

Findings

Variational scarring can occur in elliptical graphene quantum dots.

Scanning tunneling microscopy can potentially detect variational scars.

The study provides a pathway for experimental validation of quantum-chaotic phenomena.

Abstract

A quantum eigenstate of a classically chaotic system is referred as scarred by an unstable periodic orbit if its probability density is concentrated in the vicinity of that orbit. Recently, a new class of scarring - variational scarring - was discovered in numerical studies of disordered quantum dots, arising from near-degeneracies in the quantum spectrum associated with classical resonances of the unperturbed system. Despite the increasing body of theoretical evidence on variational scarring, its experimental observation has remained out of reach. Motivated by this dearth, we argue and demonstrate that variational scarring can occur in an elliptical quantum dot fabricated on monolayer graphene, and locally perturbed by a nanotip. Then, we further show that the fingerprint of these variational scars can potentially be detected via scanning tunneling microscopy, thus offering an attractive experimental pathway for the first validation of this puzzling quantum-chaotic phenomenon.