| Title: |
Spontaneous Localization at a Potential Saddle Point from Edge State Reconstruction in a Quantum Hall Point Contact |
| Authors: |
Cohen, Liam A; Samuelson, Noah L; Wang, Taige; Klocke, Kai; Reeves, Cian C; Taniguchi, Takashi; Watanabe, Kenji; Vijay, Sagar; Zaletel, Michael P; Young, Andrea F |
| Source: |
Physical Review Letters, vol 134, iss 7 |
| Publisher Information: |
eScholarship, University of California |
| Publication Year: |
2025 |
| Collection: |
University of California: eScholarship |
| Subject Terms: |
Quantum Physics; Physical Sciences; Condensed Matter Physics; Mathematical Sciences; Engineering; General Physics |
| Description: |
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. |
| Document Type: |
article in journal/newspaper |
| File Description: |
application/pdf |
| Language: |
unknown |
| Relation: |
qt9053x68v; https://escholarship.org/uc/item/9053x68v; https://escholarship.org/content/qt9053x68v/qt9053x68v.pdf |
| DOI: |
10.1103/physrevlett.134.076302 |
| Availability: |
https://escholarship.org/uc/item/9053x68v; https://escholarship.org/content/qt9053x68v/qt9053x68v.pdf; https://doi.org/10.1103/physrevlett.134.076302 |
| Rights: |
CC-BY |
| Accession Number: |
edsbas.82B5A60C |
| Database: |
BASE |