Quasiparticle Tunneling in the Fractional Quantum Hall State at \nu = 5/2

TL;DR

This paper measures quasiparticle tunneling in the fractional quantum Hall state at /2, providing experimental data that supports non-abelian state models with specific charge and interaction parameters.

Contribution

It presents the first detailed tunneling measurements at /2, testing theoretical predictions and constraining models of the states quasiparticle charge and interactions.

Findings

Data supports non-abelian /2 state with e*=1/4 and g=1/2

Tunneling conductance peaks collapse onto a universal curve with temperature scaling

Results favor non-abelian models over abelian alternatives

Abstract

Theory predicts that quasiparticle tunneling between the counter-propagating edges in a fractional quantum Hall state can be used to measure the effective quasiparticle charge e* and dimensionless interaction parameter g, and thereby characterize the many-body wavefunction describing the state. We report measurements of quasiparticle tunneling in a high mobility GaAs two dimensional electron system in the fractional quantum Hall state at nu=5/2 using a gate-defined constriction to bring the edges close together. We find the dc-bias peaks in the tunneling conductance at different temperatures collapse onto a single curve when scaled, in agreement with weak tunneling theory. Various models for the \nu=5/2 state predict different values for g. Among these models, the non-abelian states with e*=1/4 and g=1/2 are most consistent with the data.