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/Vs, respectively. Although the quality of graphene devices has also been improving, it remains comparatively lower. 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/Vs, surpassing those in the highest-quality semiconductor heterostructures by an order of magnitude, and the transport mobilities match their record. This quality enables Shubnikov-de Haas oscillations in fields as low as 1 mT and quantum Hall plateaus 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 to 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.
@article{arxiv.2507.21997,
title = {Proximity screening greatly enhances electronic quality of graphene},
author = {Daniil Domaretskiy and Zefei Wu and Van Huy Nguyen and Ned Hayward and Ian Babich and Xiao Li and Ekaterina Nguyen and Julien Barrier and Kornelia Indykiewicz and Wendong Wang and Roman V. Gorbachev and Na Xin and Kenji Watanabe and Takashi Taniguchi and Lee Hague and Vladimir I. Fal'ko and Irina V. Grigorieva and Leonid A. Ponomarenko and Alexey I. Berdyugin and Andre K. Geim},
journal= {arXiv preprint arXiv:2507.21997},
year = {2025}
}