Tuning non-linear charge transport between integer and fractional quantum Hall states

TL;DR

This paper demonstrates a method to tune charge transport between different quantum Hall states using particle-hole duality, enabling precise control of fractional quasiparticle junctions and revealing a crossover from insulating to conducting behavior.

Contribution

It introduces a novel approach to realize and tune point-contact junctions between quantum Hall phases exploiting particle-hole duality, with independent control over fractional filling and coupling strength.

Findings

Observation of a crossover from insulating to conducting behavior as fractional filling varies.

Implementation of tunable point-contact junctions between quantum Hall states.

Highlighting the importance of local charge depletion in inter-edge tunneling.

Abstract

Controllable point junctions between different quantum Hall phases are a necessary building block for the development of mesoscopic circuits based on fractionally-charged quasiparticles. We demonstrate how particle-hole duality can be exploited to realize such point-contact junctions. We show an implementation for the case filling factors $\nu=1$ and $\nu^*\le1$ in which both the fractional filling $\nu^*$ and the coupling strength can be finely and independently tuned. A peculiar crossover from insulating to conducting behavior as $\nu^*$ goes from 1/3 to 1 is observed. These results highlight the key role played on inter-edge tunneling by local charge depletion at the point contact.