Measurements of quasi-particle tunneling in the nu = 5/2 fractional quantum Hall state

TL;DR

This study measures quasi-particle tunneling in the nu=5/2 fractional quantum Hall state, providing evidence that supports the Abelian 331 state over non-Abelian models, with implications for topological quantum computation.

Contribution

It presents experimental tunneling data that favor the Abelian 331 state, challenging non-Abelian models of the 5/2 fractional quantum Hall state.

Findings

Quasi-particle charge close to e/4

Interaction strength g near 3/8

Data favors Abelian 331 state

Abstract

Some models of the 5/2 fractional quantum Hall state predict that the quasi-particles, which carry the charge, have non-Abelian statistics: exchange of two quasi-particles changes the wave function more dramatically than just the usual change of phase factor. Such non-Abelian statistics would make the system less sensitive to decoherence, making it a candidate for implementation of topological quantum computation. We measure quasi-particle tunneling as a function of temperature and DC bias between counter-propagating edge states. Fits to theory give e*, the quasi-particle effective charge, close to the expected value of e/4 and g, the strength of the interaction between quasi-particles, close to 3/8. Fits corresponding to the various proposed wave functions, along with qualitative features of the data, strongly favor the Abelian 331 state.