Abstract
The unique properties of quantum hall devices arise from the ideal one-dimensional edge states that form in a two-dimensional electron system at high magnetic field. Tunnelling between edge states across a quantum point contact (QPC) has already revealed rich physics, like fractionally charged excitations, or chiral Luttinger liquid. Thanks to scanning gate microscopy, we show that a single QPC can turn into an interferometer for specific potential landscapes. Spectroscopy, magnetic field and temperature dependences of electron transport reveal a quantitatively consistent interferometric behavior of the studied QPC. To explain this unexpected behavior, we put forward a new model which relies on the presence of a quantum Hall island at the centre of the constriction as well as on different tunnelling paths surrounding the island, thereby creating a new type of interferometer. This work sets the ground for new device concepts based on coherent tunnelling.
Highlights
The unique properties of quantum hall devices arise from the ideal one-dimensional edge states that form in a two-dimensional electron system at high magnetic field
Thanks to scanning gate microscopy, we show that a single quantum point contact (QPC) can turn into an interferometer for specific potential landscapes
Temperature dependence and scanning gate spectroscopy show clear www.nature.com/scientificreports signatures of quantum interferences. Up to now, such interferences were exclusively observed in open Quantum Hall (QH) devices, this observation sets the stage for a new electron transport scenario
Summary
The unique properties of quantum hall devices arise from the ideal one-dimensional edge states that form in a two-dimensional electron system at high magnetic field. Spectroscopy, magnetic field and temperature dependences of electron transport reveal a quantitatively consistent interferometric behavior of the studied QPC To explain this unexpected behavior, we put forward a new model which relies on the presence of a quantum Hall island at the centre of the constriction as well as on different tunnelling paths surrounding the island, thereby creating a new type of interferometer. Lateral confinement, e.g. in quantum point contacts (QPC), offers the possibility to connect a QHI to ES through tunnel junctions, and form a new class of 1D-0D-1D QH devices (Fig. 1) In this case, the 0D island is characterized by a weak coupling (s = e2/h) and a large charging energy We propose a new model that provides a quantitative interpretation of the data
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