Effect of inter-edge Coulomb interactions on transport through a point contact in a ν = 5/2 quantum Hall state

¹  Institut für Festkörper-Forschung - Theorie 3, Forschungszentrum Jülich - 52425 Jülich, Germany, EU
²  Institut für Theoretische Physik A, RWTH Aachen - 52056 Aachen, Germany, EU
³  Harish-Chandra Research Institute - Chhatnag Road, Jhusi, Allahabad 211 019, India
⁴  Centre for High Energy Physics, Indian Institute of Science - Bangalore 560 012, India

Corresponding authors: s.das@fz-juelich.de sumathi@hri.res.in diptiman@cts.iisc.ernet.in

Received: 11 February 2009
Accepted: 17 April 2009

Abstract

We study transport across a point contact separating two line junctions in a ν = 5/2 quantum Hall system. We analyze the effect of inter-edge Coulomb interactions between the chiral bosonic edge modes of the half-filled Landau level (assuming a Pfaffian wave function for the half-filled state) and of the two fully filled Landau levels. In the presence of inter-edge Coulomb interactions between all the six edges participating in the line junction, we show that the stable fixed point corresponds to a point contact that is neither fully opaque nor fully transparent. Remarkably, this fixed point represents a situation where the half-filled level is fully transmitting, while the two filled levels are completely backscattered; hence the fixed point Hall conductance is given by . We predict the non-universal temperature power laws by which the system approaches the stable fixed point from the two unstable fixed points corresponding to the fully connected case and the fully disconnected case ().