Strongly coupled edge states in a graphene quantum Hall interferometer

Abstract

Electronic interferometers using the chiral, one-dimensional (1D) edge channels of the quantum Hall effect (QHE) can demonstrate a wealth of fundamental phenomena. The recent observation of phase jumps in a Fabry-Pérot (FP) interferometer revealed anyonic quasiparticle exchange statistics in the fractional QHE. When multiple integer edge channels are involved, FP interferometers have exhibited anomalous Aharonov-Bohm (AB) interference frequency doubling, suggesting putative pairing of electrons into 2e quasiparticles. Here, we use a highly tunable graphene-based QHE FP interferometer to observe the connection between interference phase jumps and AB frequency doubling, unveiling how strong repulsive interaction between edge channels leads to the apparent pairing phenomena. By tuning electron density in-situ from filling factor ν<2 to ν>7, we tune the interaction strength and observe periodic interference phase jumps leading to AB frequency doubling. Our observations demonstrate that the combination of repulsive interaction between the spin-split ν=2 edge channels and charge quantization is sufficient to explain the frequency doubling, through a near-perfect charge screening between the localized and extended edge channels. Our results show that interferometers are sensitive probes of microscopic interactions and enable future experiments studying correlated electrons in 1D channels using our highly tunable platform.

26 pages, 13 figures

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• Anyonic interference and braiding phase in a Mach-Zehnder Interferometer
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• Anyons in Quantum Hall Interferometry
• Robustness of quantum Hall interferometry
• Half-integer conductance plateau at the $\nu =2/3$ fractional quantum Hall state in a quantum point contact
• Graphene-based quantum Hall interferometer with self-aligned side gates
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• Electron Pairing of Interfering Interface-Based Edge Modes
• Slow quasiparticle dynamics and anyonic statistics in a fractional quantum Hall Fabry-Pérot interferometer
• Quantum Hall interferometry at finite bias with multiple edge channels

Cited by in corpus (12)

• Anyon braiding and telegraph noise in a graphene interferometer
• Aharonov-Bohm interference and the evolution of phase jumps in fractional quantum Hall Fabry-Perot interferometers based on bi-layer graphene
• Molecular anyons in fractional quantum Hall effect
• Evidence for correlated electron pairs and triplets in quantum Hall interferometers
• Anyon braiding on the single edge of a fractional quantum Hall state
• Quantum Hall interferometry at finite bias with multiple edge channels
• Single electron interference and capacitive edge mode coupling generates ${\Phi }_0/2$ flux periodicity in Fabry-Perot interferometers
• Probing anyon statistics on a single-edge loop in the fractional quantum Hall regime
• Spontaneous localization at a potential saddle point from edge state reconstruction in a quantum Hall point contact
• Quantum statistics and self-interference in extended colliders
• Chern junctions in Moiré-Patterned Graphene/PbI2
• Triple Antidot Molecules