Evidence for correlated electron pairs and triplets in quantum Hall interferometers
Wenmin Yang1, David Perconte1, Corentin Déprez1
1Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, Grenoble, France.
Nature Communications
|November 20, 2024
Summary
Electron pairing and tripling mediated by repulsive forces were observed in graphene Quantum Hall Fabry-Pérot interferometers. This correlated charge transport involves entangled edge channels, revealing unusual electronic behaviors.
Area of Science:
- Condensed Matter Physics
- Quantum Phenomena
Background:
- Electron pairing is common in systems with attractive interactions, like superconductors.
- Repulsive Coulomb interactions can also mediate electron pairing under specific conditions.
- Quantum Hall (QH) Fabry-Pérot interferometers (FPIs) in 2D electron gases are platforms to study these phenomena.
Purpose of the Study:
- To investigate electron pairing mediated by repulsive forces in graphene QH FPIs.
- To explore emergent phenomena, such as electron tripling, in these systems.
- To elucidate the role of entangled quantum Hall edge channels in correlated transport.
Main Methods:
- Fabrication of graphene QH FPIs.
- Perpendicular magnetic field application.
- Plunger-gate spectroscopy to probe electron transport.
- Analysis of Aharonov-Bohm flux periodicity.
Main Results:
- Evidence of electron pairing at bulk filling factor νB = 2.
- Observation of electron tripling with a fractional Aharonov-Bohm flux period of h/3e at νB = 3.
- Demonstration that pairing/tripling involves correlated transport on two/three entangled QH edge channels.
- Quantum interference flux periodicity determined by the sum of phases from distinct edge channels.
Conclusions:
- Graphene QH FPIs exhibit unusual electron pairing and tripling mediated by repulsive interactions.
- Correlated charge transport on entangled QH edge channels is responsible for these phenomena.
- The observed flux periodicity provides insights into the phase accumulation in interfering edge channels.
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