Low-frequency impedance of quantized Hall conductors

The longitudinal and the Hall impedances have been measured as a function o f the frequency in a two-dimensional electron gas at low temperatures. The frequency dependence of the longitudinal impedance can be explained in term s of an equivalent parallel LCR circuit. An effective inductance term arise s due to the capacitive coupling between edge states and is shown to scale as 1/v(2) for different fillings factors. In the low-frequency range the re lative difference between the ac and de values of the Hall impedance is fou nd to depend quadratically on the frequency and to scale as 1/v(3). These r esults are shown to be consistent with the existing theoretical model based on the edge-state picture. Finally, the observed symmetry relations when e xchanging current contacts or reversing magnetic field are discussed.