Interference measurements of non-Abelian e/4 & Abelian e/2 quasiparticle braiding.
The quantum Hall states at filling factors 5/2 and 7/2 are expected to have Abelian charge e/2 quasiparticles and non-Abelian charge e/4 quasiparticles. We test this by measuring resistance oscillations as a function of magnetic field in quantum Hall Fabry-Perot interferometers. At filling factor 5/2 they have four dominant frequencies, as expected for transport due to these two types of quasiparticles. At 7/2 filling a different set of frequencies is expected, and the measured oscillations match those. Furthermore, our results indicate that the e/4 oscillations are stable against fermionic parity fluctuations over long times (hours) near 5/2 and 72. The observed stability further strengthens the case for using non-Abelian e/4 quasiparticles for topological quantum computation.