Coulomb Oscillations in Antidots in the Integer and Fractional Quantum Hall Regimes

We present measurements of Coulomb oscillations as a function of both top gate and magnetic field in gate-defined, micron-scale antidots in the integer and fractional quantum Hall regimes. We find resistance oscillations at filling factors $\nu=2,\nu=1,\nu=2/3,$ and $\nu=1/3$. At $\nu=1$, we find the tunneling charge to be $e$ and the presence of one edge. At $\nu=2$, we also find the tunneling charge to be $e$ and the presence of two edges. A generalized picture of Coulomb oscillations in the fractional quantum Hall regime suggests the presence of one charged edge at both $\nu=1/3$ and $\nu=2/3$. We find the tunneling charge at $\nu=1/3$ to be $e/3$ but unexpectedly find the tunneling charge at $\nu=2/3$ to be $(2/3)e$.