Observation of current whirlpools in graphene at room temperature

• 成果类型: Article
• 署名作者: Palm, Marius L.; Ding, Chaoxin; Huxter, William S.; Taniguchi, Takashi; Watanabe, Kenji; Degen, Christian L.
• 署名单位: Swiss Federal Institutes of Technology Domain; ETH Zurich; National Institute for Materials Science; National Institute for Materials Science; Swiss Federal Institutes of Technology Domain; ETH Zurich
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-10789
• DOI: 10.1126/science.adj2167
• 发表日期: 2024-04-26
• 页码: 465-469
• 关键词: electron; transport; FLOW; resistance; vortices

摘要

Electron-electron interactions in high-mobility conductors can give rise to transport signatures resembling those described by classical hydrodynamics. Using a nanoscale scanning magnetometer, we imaged a distinctive hydrodynamic transport pattern-stationary current vortices-in a monolayer graphene device at room temperature. By measuring devices with increasing characteristic size, we observed the disappearance of the current vortex and thus verified a prediction of the hydrodynamic model. We further observed that vortex flow is present for both hole- and electron-dominated transport regimes but disappears in the ambipolar regime. We attribute this effect to a reduction of the vorticity diffusion length near charge neutrality. Our work showcases the power of local imaging techniques for unveiling exotic mesoscopic transport phenomena.