Microwave Absorption by a Mesoscopic Quantum Hall Droplet

TL;DR

This paper demonstrates how microwave absorption measurements on a quantum Hall droplet can reveal detailed edge mode properties, quasiparticle statistics, and different edge regimes, offering a new experimental approach beyond standard transport methods.

Contribution

It introduces a method to directly measure edge mode velocities, count, and quasiparticle braiding statistics via microwave absorption in quantum Hall droplets.

Findings

Edge mode velocities and numbers can be directly measured.

Different edge equilibration regimes are accessible within a single device.

Quasiparticle braiding statistics can be inferred from absorption spectrum modulations.

Abstract

We consider the absorption of microwaves by a quantum Hall droplet. We show that the number and velocities of charged edge modes can be directly measured from a droplet of known shape. In contrast to standard transport measurements, different edge equilibration regimes can be accessed in the same device. If there is a quantum point contact in the droplet, then quasiparticle properties, including braiding statistics, can be observed. Their effects are manifested as modulations of the microwave absorption spectrum that are, notably, first-order in the tunneling amplitude at the point contact.