Topological dephasing in the $\nu=2/3$ fractional Quantum Hall Regime

TL;DR

This paper investigates how electron fractionalization and fractional statistics in a quantum dot within the fractional quantum Hall regime cause dephasing, selectively suppressing certain interference oscillations and leading to halved oscillation periods.

Contribution

It reveals a novel dephasing mechanism in fractional quantum Hall systems caused by fractionalization and fractional statistics affecting interference patterns.

Findings

Dephasing suppresses $h/e$ oscillations but not $h/(2e)$ oscillations.

Electron fractionalization leads to oscillation-period halving.

Dephasing occurs prominently at higher temperatures and specific edge mode velocity conditions.

Abstract

We study dephasing in electron transport through a large quantum dot (a Fabry-Perot interferometer) in the fractional quantum Hall regime with filling factor $2/3$. In the regime of sequential tunneling, dephasing occurs due to electron fractionalization into counterpropagating charge and neutral edge modes on the dot. In particular, when the charge mode moves much faster than the neutral mode, and at temperatures higher than the level spacing of the dot, electron fractionalization combined with tje fractional statistics of the charge mode leads to the dephasing selectively suppressing $h/e$ Aharonov-Bohm oscillations but not $h/(2e)$ oscillations, resulting in oscillation-period halving.