Abstract
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 /πħ when the width, controlled by a gate on top of heterojunction, is varied. Up to sixteen steps are observed when the point contact is widened from 0 to 360 nm. An explanation is proposed, which assumes quantized transverse momentum in the point-contact region.
- Received 31 December 1987
DOI:https://doi.org/10.1103/PhysRevLett.60.848
©1988 American Physical Society