Experimental probe of topological orders and edge excitations in the second Landau level

We measure weak quasiparticle tunneling across a constriction in the second Landau level. At nu = 7/3, 8/3, and 5/2, comparison of temperature and dc bias dependence to weak tunneling theory allows extracting parameters that describe the edges' quasiparticle excitations. At nu = 8/3, our results are well described by a particle-hole conjugate Laughlin state but not compatible with the proposed non-Abelian quasiparticle excitations. For nu = 5/2, our measurements are in good agreement with previous experiments and favor the Abelian (3,3,1) or (1,1,3) states. At these filling factors, we further investigate the influence of the backscattering strength on the extracted scaling parameters. For nu = 7/3, the backscattering strength strongly affects the scaling parameters, whereas quasiparticle tunneling at nu = 8/3 and 5/2 appears more robust. Our results provide important additional insight about the physics in the second Landau level and contribute to the understanding of the physics underlying the fractional quantum Hall states at nu = 7/3, 8/3, and 5/2.