Interaction Driven Quantum Hall Wedding cake-like Structures in Graphene Quantum Dots

TL;DR

This paper visualizes how electron interactions in graphene create a layered 'wedding cake' structure of quantum Hall states, revealing complex quantum-relativistic phenomena through spectroscopic mapping.

Contribution

It provides the first direct spatial visualization of interaction-driven quantum Hall structures in graphene, highlighting the interplay of confinement and electron interactions.

Findings

Observation of multi-tiered quantum Hall structures

Visualization of compressible and incompressible regions

Insight into quantum-relativistic matter behavior

Abstract

Quantum-relativistic matter is ubiquitous in nature; however it is notoriously difficult to probe. The ease with which external electric and magnetic fields can be introduced in graphene opens a door to creating a table-top prototype of strongly confined relativistic matter. Here, through a detailed spectroscopic mapping, we provide a spatial visualization of the interplay between spatial and magnetic confinement in a circular graphene resonator. We directly observe the development of a multi-tiered "wedding cake"-like structure of concentric regions of compressible/incompressible quantum Hall states, a signature of electron interactions in the system. Solid-state experiments can therefore yield insights into the behaviour of quantum-relativistic matter under extreme conditions.