Aharonov-Bohm interference of fractional quantum Hall edge modes

We demonstrate operation of a small Fabry-Perot interferometer in which highly coherent Aharonov-Bohm oscillations are observed in the integer and fractional quantum Hall regimes. Using a novel heterostructure design, Coulomb effects are drastically suppressed. Coherency of edge mode interference is characterized by the energy scale for thermal damping, ${T_0=206}mK$ at $\nu=1$. Selective backscattering of edge modes originating in the ${N=0,1,2}$ Landau levels allows for independent determination of inner and outer edge mode velocities. Clear Aharonov-Bohm oscillations are observed at fractional filling factors $\nu=2/3$ and $\nu=1/3$. Our device architecture provides a platform for measurement of anyonic braiding statistics.
Comment: 18 pages, 11 figures. A revised version of this manuscript and supplementary material will appear in Nature Physics