Observation of excess conductance of a constricted electron gas in the fractional quantum Hall regime.

We present experimental results on the conductance of a two-dimensional electron System of f i l l ing factor i/2i) in the fractional quantum Hal l regime, containing a constricted region of Iower f i l l i n g factor v,. Conductance f luctuat ions are observed as a function of the voltage on the gate defming the constriction. The temperature dependence of the fluctuations exhibits three distinct regimes, governed by v,. For temperatures below 100 mK, and for vi» y , one anomalous peak increases to a value above the quanti/ed conductance V2o(e/h) of the bulk.