扭转菱方石墨烯家族中的自旋极化超导与高陈数绝缘体

中文摘要 AI 辅助

菱方多层石墨烯已成为探索由低能拓扑平带引发的强关联量子态的一个极其通用的平台。当通过莫尔超晶格重构时，这些平带承载了多种涌现的新奇态，包括整数和分数量子陈绝缘体以及非常规超导。在此，我们首次报道了在扭转双层多层RMG体系2+n（其中n=4,5,6）中同时出现广泛的自旋极化超导和高陈数绝缘体。2+n体系中的超导态对平面内磁场的响应不同，超导可被平面内磁场抑制、增强或诱导。后两种响应与自旋三重态配对一致。伴随超导，出现了角度和层数依赖的、具有可调陈数的高陈数绝缘体。此外，体系中的分数量子高陈数绝缘体在高平面内磁场下仍然存在，而该磁场可在同一器件中诱导超导。我们的工作不仅确立了扭转双层多层菱方石墨烯作为研究超导和高陈数绝缘体的统一平台，而且通过将自旋极化超导与高陈数绝缘体耦合，为多条共传播手性马约拉纳通道开辟了途径。

英文摘要

Rhombohedral multilayer graphene has emerged as a remarkably versatile platform for exploring strong correlation driven quantum states arising from low-energy topological flat bands. When reconstructed by the moire superlattice, these bands host a wide range of emergent novel states, including integer and fractional Chern insulators and unconventional superconductivity. Here, we firstly report the simultaneous emergence of widespread spin polarized SC and high Chern insulators in twisted bilayer multilayer RMG system 2+n where n=4,5,6. The SC states in 2+n system exhibit different responses to the in plane magnetic field, with SC being suppressed, enhanced and induced by in plane magnetic field . The latter two are consistent with spin-triplet pairing. Along with SC, angle and layer dependent HCIs with tunable Chern numbers emerge. Moreover, the fractional high Chern insulator in the system survives under high in plane magnetic field which can induce SC in the same device. Our work not only establishs twisted bilayer multilayer rhombohedral graphene as a unified platform for studying SC and high Chern insulators, but also opens a pathway towards multiple copropagating chiral Majorana channels by coupling spin-polarized SC to high Chern insulators.

发表机构

• International Center for Quantum Materials, School of Physics, Peking University（北京大学物理学院量子材料国际中心）
• State Key Laboratory for Mesoscopic Physics, Frontiers Science Centre for Nano-optoelectronics, School of Physics, Peking University（北京大学物理学院介观物理国家重点实验室纳米光电子前沿科学中心）
• Research Center for Electronic and Optical Materials, National Institute for Material Science（日本国立物质材料研究所电子与光学材料研究中心）
• Research Center for Materials Nanoarchitectonics, National Institute for Material Science（日本国立物质材料研究所材料纳米结构研究中心）
• Interdisciplinary Institute of Light-Element Quantum Materials and Research Centre for Light-Element Advanced Materials, Peking University（北京大学轻元素量子材料交叉研究院轻元素先进材料研究中心）

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