Proximity screening greatly enhances electronic quality of graphene

• 成果类型: Article
• 署名作者: Domaretskiy, Daniil; Wu, Zefei; Nguyen, Van Huy; Hayward, Ned; Babich, Ian; Li, Xiao; Nguyen, Ekaterina; Barrier, Julien; Indykiewicz, Kornelia; Wang, Wendong; Gorbachev, Roman V.; Xin, Na; Watanabe, Kenji; Taniguchi, Takashi; Hague, Lee; Fal'ko, Vladimir I.; Grigorieva, Irina V.; Ponomarenko, Leonid A.; Berdyugin, Alexey I.; Geim, Andre K.
• 署名单位: University of Manchester; University of Manchester; National University of Singapore; National University of Singapore; National Institute for Materials Science; Lancaster University
• 刊物名称: Nature
• ISSN/ISSBN: 0028-1492
• DOI: 10.1038/s41586-025-09386-0
• 发表日期: 2025-08-21
• 关键词: dirac plasma; quantum; mobility; transport; heterostructures; physics; gas; mbe

摘要

The electronic quality of two-dimensional systems is crucial when exploring quantum transport phenomena. In semiconductor heterostructures, decades of optimization have yielded record-quality two-dimensional gases with transport and quantum mobilities reaching close to 108 and 106 cm2 V-1 s-1, respectively1, 2, 3, 4, 5, 6, 7, 8, 9-10. Although the quality of graphene devices has also been improving, it remains comparatively lower11, 12, 13, 14, 15, 16-17. Here we report a transformative improvement in the electronic quality of graphene by employing graphite gates placed in its immediate proximity, at 1 nm separation. The resulting screening reduces charge inhomogeneity by two orders of magnitude, bringing it down to a few 107 cm-2 and limiting potential fluctuations to less than 1 meV. Quantum mobilities reach 107 cm2 V-1 s-1, surpassing those in the highest-quality semiconductor heterostructures by an order of magnitude, and the transport mobilities match their record9,10. This quality enables Shubnikov-de Haas oscillations in fields as low as 1 mT and quantum Hall plateaux below 5 mT. Although proximity screening predictably suppresses electron-electron interactions, fractional quantum Hall states remain observable with their energy gaps reduced only by a factor of 3-5 compared with unscreened devices, demonstrating that many-body phenomena at spatial scales shorter than 10 nm remain robust. Our results offer a reliable route to improving electronic quality in graphene and other two-dimensional systems, which should facilitate the exploration of new physics previously obscured by disorder.