We report an observation of the lateral quantum-interference effects of a two-dimensional electron gas in a narrow-wide-narrow conducting path fabricated from ${\mathrm{Al}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{-}\mathit{x}}$As/GaAs heterostructures constructed with a corrugated metal gate. The phase of the electron wave function is controlled by the gate voltages in such a way that the peak positions of the oscillations in the conductance vs the gate voltage agree well with the conditions for the lateral quantum-interference effect. Also observed, for the first time to the best of our knowledge, is a multiple-quantum-reflection effect caused by the gate potential steps.

• Received 10 November 1994

DOI:https://doi.org/10.1103/PhysRevB.51.13805