Measurements of quasiparticle tunneling in the υ=5/2 fractional quantum Hall state

Some models of the 5/2 fractional quantum Hall state predict that the quasiparticles, which carry the charge, have non-Abelian statistics: exchange of two quasiparticles 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 quasiparticle tunneling as a function of temperature and dc bias between counterpropagating edge states. Fits to theory give e*, the quasiparticle effective charge, close to the expected value of e/4 and g, the strength of the interaction between quasiparticles, 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.