Quantized conductance of point contacts in a two-dimensional electron gas

Ballistic point contacts, defined in the two-dimensional electron gas of a GaAs-AlGaAs heterostructure, have been studied in zero magnetic field. The conductance changes in quantized steps of ${e}^{2}$/\ensuremath{\pi}\ensuremath{\Elzxh} when the width, controlled by a gate on top of heterojunction,... View More