近日，英国曼彻斯特大学Geim, Andre K.团队通过近距离筛选大大提高了石墨烯的电子质量。这一研究成果发表在2025年8月20日出版的《自然》杂志上。

在探索量子输运现象时，二维系统的电子质量至关重要。在半导体异质结构中，几十年的优化产生了创纪录质量的二维气体，其输运和量子迁移率接近108和106 cm2 V−1 s−1。尽管石墨烯器件的质量也在提高，但仍然相对较低。

研究组报告了石墨烯电子质量的变革性改进，通过在石墨烯附近放置石墨门，在1 nm处分离。由此产生的屏蔽将电荷不均匀性降低了两个数量级，使其降至107 cm-2，并将电位波动限制在1meV以下。

量子迁移率达到107 cm2 V−1 s-1，比最高质量半导体异质结构中的传输迁移率高出一个数量级，传输迁移率与他们的记录相匹配。

这种特性使舒布尼科夫-德哈斯振荡在低至1mT和量子霍尔平台低于5mT。尽管邻近屏蔽可以预测地抑制电子-电子相互作用，但分数量子霍尔态仍然可以观察到，与未屏蔽的器件相比，它们的能隙仅减少了3-5倍，这表明在小于10nm的空间尺度上，许多体现象仍然是稳健的。我们的研究结果为提高石墨烯和其他二维系统的电子质量提供了一条可靠的途径，这将有助于探索以前被无序所掩盖的新物理学。

附：英文原文

Title: Proximity screening greatly enhances electronic quality of graphene

Author: 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, Falko, Vladimir I., Grigorieva, Irina V., Ponomarenko, Leonid A., Berdyugin, Alexey I., Geim, Andre K.

Issue&Volume: 2025-08-20

Abstract: 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 106cm2V1s1, 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 1nm separation. The resulting screening reduces charge inhomogeneity by two orders of magnitude, bringing it down to a few 107cm2 and limiting potential fluctuations to less than 1meV. Quantum mobilities reach 107cm2V1s1, 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 1mT and quantum Hall plateaux below 5mT. 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 10nm 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.

DOI: 10.1038/s41586-025-09386-0

Source: https://www.nature.com/articles/s41586-025-09386-0

来源：科学网 小柯机器人