Detection of Coulomb Charging around an Antidot in the Quantum Hall Regime

TL;DR

This paper reports the detection of Coulomb charging oscillations around an antidot in a quantum Hall system, revealing a new Coulomb blockade phenomenon influenced by magnetic field-induced electron confinement.

Contribution

It introduces a novel Coulomb blockade effect observed around an antidot in the quantum Hall regime, confirmed through charge oscillations and spectroscopic measurements.

Findings

Charge oscillations are observed as a function of magnetic field.

Coulomb blockade behavior is confirmed via addition and excitation spectra.

The phenomenon demonstrates a new form of Coulomb blockade in quantum Hall systems.

Abstract

We have detected oscillations of the charge around a potential hill (antidot) in a two-dimensional electron gas as a function of a large magnetic field B. The field confines electrons around the antidot in closed orbits, the areas of which are quantised through the Aharonov-Bohm effect. Increasing B reduces each state's area, pushing electrons closer to the centre, until enough charge builds up for an electron to tunnel out. This is a new form of the Coulomb blockade seen in electrostatically confined dots. Addition and excitation spectra in DC bias confirm the Coulomb blockade of tunnelling.