Coulomb oscillations of a quantum antidot formed by an airbridged pillar gate in the integer and fractional quantum Hall regime

TL;DR

This study demonstrates Coulomb oscillations in a quantum antidot device across integer and fractional quantum Hall regimes, revealing charge quantization and area differences, with potential for quasiparticle manipulation.

Contribution

It introduces a novel quantum antidot formed by an airbridged pillar gate, analyzing Coulomb oscillations and effective charge in both integer and fractional quantum Hall states.

Findings

The QAD area at ν=2/3 is smaller than at ν=2 and 1.

Effective charge at ν=2/3 is approximately 2/3 of that at ν=2 and 1.

The device can capture and emit charges in units of 2e/3.

Abstract

Quantum antidots (QAD) are attractive for manipulating quasiparticles in quantum Hall (QH) systems. Here, we form a QAD in the integer and fractional QH regimes at nominal Landau-level filling factor $\nu$ = 2, 1, and 2/3 using a submicron pillar gate with an airbridge connection. After confirming the required conditions for a fully depleted QAD, we analyze the observed Coulomb oscillations in terms of the area of the QAD and the effective charge for the oscillation period in an identical gate voltage range. The area at $\nu$ = 2/3 is significantly smaller than that at $\nu$ = 2 and 1, in qualitative agreement with the previous report. By assuming a constant gate capacitance, the effective charge at $\nu$ = 2/3 is about 2/3 of that at $\nu$ = 2 and 1. The QAD device can be used to capture and emit charges in the unit of 2e/3.