Spontaneous localization at a potential saddle point from edge state reconstruction in a quantum Hall point contact
arXiv:2401.10433 · doi:10.1103/PhysRevLett.134.076302
Abstract
Quantum point contacts (QPCs) are an essential component in mesoscopic devices. Here, we study the transmission of quantum Hall edge modes through a gate-defined QPC in monolayer graphene. We observe resonant tunneling peaks and a nonlinear conductance pattern characteristic of Coulomb-blockaded localized states. The in-plane electric polarizability reveals the states are localized at a classically-unstable electrostatic saddle point. We explain this unexpected finding within a self-consistent Thomas-Fermi model, finding that localization of a zero-dimensional state at the saddle point is favored whenever the applied confinement potential is sufficiently soft compared to the Coulomb energy. Our results provide a direct demonstration of Coulomb-driven reconstruction at the boundary of a quantum Hall system.
arXiv comment15 pages, 10 figures. arXiv admin note: text overlap with arXiv:2204.10296
References in corpus (19)
- Sharp and Smooth Boundaries of Quantum Hall Liquids
- Local Thermometry of Neutral Modes on the Quantum Hall Edge
- A New Paradigm for Edge Reconstruction in Fractional Quantum Hall States
- Aharonov Bohm Effect in Graphene Fabry Pérot Quantum Hall Interferometers
- A tunable Fabry-Pérot quantum Hall interferometer in graphene
- Evolution of Landau Levels into Edge States at an Atomically Sharp Edge in Graphene
- Melting of interference in the fractional quantum Hall effect: Appearance of neutral modes
- Quasinormal Modes and Hawking-Unruh effect in Quantum Hall Systems: Lessons from Black Hole Phenomena
- Experimental determination of the energy per particle in partially filled Landau levels
- Tunable transmission of quantum Hall edge channels with full degeneracy lifting in split-gated graphene devices
- Fractional Edge Reconstruction in Integer Quantum Hall Phases
- Realizing Universal Edge Properties in Graphene Fractional Quantum Hall Liquids
- Universal chiral Luttinger liquid behavior in a graphene fractional quantum Hall point contact
- Nanoscale electrostatic control in ultra clean van der Waals heterostructures by local anodic oxidation of graphite gates
- Strongly coupled edge states in a graphene quantum Hall interferometer
- Interplay of fractional quantum Hall states and localization in quantum point contacts
- Graphene-based quantum Hall interferometer with self-aligned side gates
- Aharonov-Bohm oscillations in bilayer graphene edge state Fabry-Pérot interferometers
- Transmission coefficient through a saddle-point electrostatic potential for graphene in the quantum Hall regime