Tuning nonlinear charge transport between integer and fractional quantum Hall states.
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.
Roddaro
Stefano
S
NEST, Scuola Normale Superiore and CNR-INFM, Piazza dei Cavalieri 7, I-56126 Pisa, Italy.
Paradiso
Nicola
N
Pellegrini
Vittorio
V
Biasiol
Giorgio
G
Sorba
Lucia
L
Beltram
Fabio
F