Transport spectroscopy of a Coulomb island in the quantum Hall regime

Transport measurements of a Coulomb island, a semiconductor dot small enough that Coulomb interactions dominate transport are presented. At moderate magnetic fields (B=2--4 T) the amplitude and position of the Coulomb-regulated conductance peaks show distinct periodic structure as a function of B. This structure is shown to result from the B dependence of the quantized single-particle energy states on the island. Analysis of successive peaks is used to map out the single-particle level spectrum of the island as a function of B.