Suppr超能文献

自旋轨道耦合双层石墨烯中的扭转可编程超导性。

Twist-programmable superconductivity in spin-orbit-coupled bilayer graphene.

作者信息

Zhang Yiran, Shavit Gal, Ma Huiyang, Han Youngjoon, Siu Chi Wang, Mukherjee Ankan, Watanabe Kenji, Taniguchi Takashi, Hsieh David, Lewandowski Cyprian, von Oppen Felix, Oreg Yuval, Nadj-Perge Stevan

机构信息

T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, CA, USA.

Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, CA, USA.

出版信息

Nature. 2025 May;641(8063):625-631. doi: 10.1038/s41586-025-08959-3. Epub 2025 May 7.

Abstract

The relative twist angle between layers of near-lattice-matched van der Waals materials is critical for the emergent phenomena associated with moiré flat bands. However, the concept of angle rotation control is not exclusive to moiré superlattices in which electrons directly experience a twist-angle-dependent periodic potential. Instead, it can also be used to induce programmable symmetry-breaking perturbations with the goal of stabilizing desired correlated states. Here we experimentally demonstrate 'moiréless' twist-tuning of superconductivity together with other correlated orders in Bernal bilayer graphene proximitized by tungsten diselenide. The precise alignment between the two materials systematically controls the strength of induced Ising spin-orbit coupling (SOC), profoundly altering the phase diagram. As Ising SOC is increased, superconductivity onsets at a higher displacement field and features a higher critical temperature, reaching up to 0.5 K. Within the main superconducting dome and in the strong Ising SOC limit, we find an unusual phase transition characterized by a nematic redistribution of holes among trigonally warped Fermi pockets and enhanced resilience to in-plane magnetic fields. The superconducting behaviour is theoretically compatible with the prominent role of interband interactions between symmetry-breaking Fermi pockets. Moreover, we identify two additional superconducting regions, one of which descends from an inter-valley coherent normal state and shows a Pauli-limit violation ratio exceeding 40, among the highest for all known superconductors. Our results provide insights into ultraclean graphene superconductors and underscore the potential of utilizing moiréless-twist engineering across a wide range of van der Waals heterostructures.

摘要

近晶格匹配的范德华材料各层之间的相对扭转角对于与莫尔平带相关的新兴现象至关重要。然而,角度旋转控制的概念并非仅限于电子直接经历与扭转角相关的周期性势的莫尔超晶格。相反,它还可用于诱导可编程的对称性破缺微扰,以稳定所需的关联态。在此,我们通过实验证明了在由二硒化钨近邻的伯纳尔双层石墨烯中,超导性以及其他关联序的“无莫尔”扭转调谐。两种材料之间的精确对准系统地控制了诱导的伊辛自旋轨道耦合(SOC)的强度,深刻地改变了相图。随着伊辛SOC的增加,超导性在更高的位移场处开始,且具有更高的临界温度,最高可达0.5 K。在主要超导穹顶内以及在强伊辛SOC极限下,我们发现了一种不寻常的相变,其特征是在三角扭曲的费米口袋之间空穴的向列型重新分布以及对平面内磁场的增强抗性。超导行为在理论上与对称性破缺费米口袋之间的带间相互作用的突出作用相一致。此外,我们还确定了另外两个超导区域,其中一个区域从谷间相干正常态下降,并且显示出超过40的泡利极限违反率,这在所有已知超导体中是最高的之一。我们的结果为超清洁石墨烯超导体提供了见解,并强调了在广泛的范德华异质结构中利用无莫尔扭转工程的潜力。

文献AI研究员

20分钟写一篇综述,助力文献阅读效率提升50倍。

立即体验

用中文搜PubMed

大模型驱动的PubMed中文搜索引擎

马上搜索

文档翻译

学术文献翻译模型,支持多种主流文档格式。

立即体验