Abstract
We study the magneto-conductance of a 1.4 μ m-wide quantum dot in the fractional quantum Hall regime. For a filling factor ≈ 2/3 and 1/3 in the quantum dot the observed Coulomb resonances show a periodic modulation in magnetic field. This indicates a non-trivial reconstruction of the 2/3 fractional quantum Hall state in the quantum dot. We present a model for the charge stability diagram of the system assuming two compressible regions separated by an incompressible stripe of filling factor 2/3 and 1/3, respectively. From the dependence of the magnetic field period on total magnetic field we construct the zero-field charge density distribution in the quantum dot. The tunneling between the two compressible regions exhibits fractional Coulomb blockade. For both filling factor regions, we extract a fractional charge e^*/e = 0.32 ± 0.03 by comparing to measurements at filling factor 2. With their close relation to quantum Hall Fabry-P\'{e}rot interferometers, our investigations on quantum dots in the fractional quantum Hall regime extend and complement interference experiments investigating the nature of anyonic fractional quantum Hall quasiparticles.