Meandering conduction channels and the tunable nature of quantized charge transport

• 成果类型: Article
• 署名作者: Doucot, Benoit; Kovrizhin, Dmitry; Moessner, Roderich
• 署名单位: Centre National de la Recherche Scientifique (CNRS); Sorbonne Universite; Centre National de la Recherche Scientifique (CNRS); CY Cergy Paris Universite; Max Planck Society
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-15351
• DOI: 10.1073/pnas.2410703121
• 发表日期: 2024-09-24
• 关键词: electronic states; edge states; quantum; metrology

摘要

The discovery of the quantum Hall effect has established the foundation of the field of topological condensed matter physics. An amazingly accurate quantization of the Hall conductance, now enshrined in quantum metrology, is stable against any reasonable perturbation due to its topological protection. Conversely, the latter implies a form of censorship by concealing any local information from the observer. The spatial distribution of the current in a quantum Hall system is such a piece of information, which, thanks to spectacular recent advances, has now become accessible to experimental probes. It is an old question whether the original and intuitively compelling theoretical picture of the current, flowing in a narrow channel along the sample edge, is the physically correct one. Motivated by recent experiments locally (2023)], we theoretically demonstrate the possibility of a broad edge state generically meandering away from the sample boundary deep into the bulk. Further, we show that by varying experimental parameters one can continuously tune between the regimes with narrow edge states and meandering channels, all the way to the charge transport occurring primarily within the bulk. This accounts for various features observed in, topological condensed matter physics, but also unveil the phenomenological richness, to be discovered.