OBSERVATION OF EXCESS CONDUCTANCE OF A CONSTRICTED ELECTRON-GAS IN THE FRACTIONAL QUANTUM HALL REGIME

[摘要] We present experimental results on the conductance of a two-dimensional electron system of filling factor nu(2D) in the fractional quantum Hall regime, containing a constricted region of lower filling factor nu(c). Conductance fluctuations are observed as a function of the voltage on the gate defining the constriction. The temperature dependence of the fluctuations exhibits three distinct regimes, governed by nu(c). For temperatures below 100 mK, and for nu(2D) = 1/3, one anomalous peak increases to a value above the quantized conductance nu(2D)(e2/h) of the bulk.

[关键词] REFLECTION PROBABILITIES;RESISTANCE FLUCTUATIONS;EDGE CHANNELS;TRANSMISSION;OSCILLATIONS;HETEROSTRUCTURES;DENSITY;CHARGE;V=2/3;V=1