Graphene quantum dots probed by scanning tunneling spectroscopy and transport spectroscopy after local anodic oxidation

TL;DR

This paper reviews recent advances in probing the wave functions of graphene quantum dots using scanning tunneling and transport spectroscopy, highlighting progress on metal-supported dots and prospects for insulating supports.

Contribution

It demonstrates how wave functions of graphene quantum dots can be mapped during transport spectroscopy, addressing previous control limitations.

Findings

Successful mapping of wave functions on metal supports

Potential methods for probing on insulating supports

Enhanced understanding of edge configuration effects

Abstract

Graphene quantum dots are considered as promising alternatives to quantum dots in III-V semiconductors, e.g., for the use as spin qubits due to their consistency made of light atoms including spin-free nuclei which both imply relatively long spin decoherene times. However, this potential has not been realized in experiments so far, most likely, due to a missing control of the edge configurations of the quantum dots. Thus, a more fundamental investigation of Graphene quantum dots appears to be necessary including a full control of the wave function properties most favorably during transport spectroscopy measurements. Here, we review the recent success in mapping wave functions of graphene quantum dots supported by metals, in particular Ir(111), and show how the goal of probing such wave functions on insulating supports during transport spectroscopy might be achieved.