Tuning nonlinear charge transport between integer and fractional quantum Hall states

Phys Rev Lett. 2009 Jul 3;103(1):016802. doi: 10.1103/PhysRevLett.103.016802. Epub 2009 Jun 29.

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 of two quantum Hall liquids at filling factors nu=1 and nu*<or=1 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 interedge tunneling by local charge depletion at the point contact.