DMREF: Collaborative Research: The Search for Novel Superconductors in Moire Flat Bands

DMREF：合作研究：在莫尔平带中寻找新型超导体

• 批准号: 1922172
• 负责人: Philip Kim
• 金额: $ 87.5万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-10-01 至 2023-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1922172&HistoricalAwards=false
• 关键词: DMREF; Collaborative; Research; Search; Novel

Non-technical Description: This project will investigate novel unconventional superconductors based on atomically thin materials stacked with a twisted angle between them. When two atomic layers with similar atomic structure meet each other, a larger scale quasi periodic structure called a moire pattern forms. Electronic structure of these interfacial structure can be engineered by adjusting the twisting angle. When the electron energy distribution is narrow, strong correlation between them appear, which can in turn drive the system to be a dissipationless superconducting state. Experimental and theoretical research, in conjunction with the predictive powers of advanced computational methods, will be developed to achieve a better understanding of the physical mechanisms at work and will contribute to the ability to design superconducting materials with higher transition temperatures. The project will provide fundamental understanding of the materials properties and phenomena that underpin superconducting electronic device applications in low energy electronics, quantum sensing, and more importantly quantum computing applications. A new generation of scientists will be trained who are deeply involved in both experimental and theoretical/modeling research with complimentary expertise.Technical Description: The moire heterostructure engineering of 2-dimensional (2D) van der Waals (vdW) materials leads to quantum heterostructures. Utilizing recently demonstrated twisted vdW heteroepitaxy, the investigators will construct vdW homo/hetero structures to realize correlated electronic states that appear in the moire flat bands. With inputs from theory and mathematical modeling of multiscale electronic structure, the project will experimentally investigate multilayer 2D superconducting systems with unusual properties, such as gate tunable transition temperature and non-conventional pairing symmetries. Various material platforms will be explored including twisted double bilayer graphene, twisted trilayer graphene and twisted homo- and hetetro-structures based on transition metal dichalcogenides. Theoretical guidance will be an indispensable part of this study since there are a variety of choices for material platforms and twist angle which cannot be covered by experiment alone without targeted modeling guide. Unconventional superconductivity can also lead into the development and discovery of topological superconductors, which can be utilized for quantum computing. The qubits realized in topological superconducting systems hold promise for fault-tolerant quantum computation, thanks to the topological nature of the underlying quantum states.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

非技术描述：该项目将研究基于原子薄材料的新型非常规超导体，这些材料之间以扭曲角度堆叠。当具有相似原子结构的两个原子层彼此相遇时，会形成更大尺度的准周期结构，称为莫尔图案。这些界面结构的电子结构可以通过调整扭转角度来设计。当电子能量分布较窄时，它们之间出现强相关性，进而驱动系统处于无耗散超导状态。实验和理论研究与先进计算方法的预测能力相结合，将得到发展，以更好地理解工作中的物理机制，并将有助于设计具有更高转变温度的超导材料的能力。该项目将提供对支撑超导电子器件在低能电子、量子传感以及更重要的量子计算应用中应用的材料特性和现象的基本了解。新一代科学家将接受培训，他们深入参与实验和理论/建模研究，并具有互补的专业知识。技术描述：二维 (2D) 范德华 (vdW) 材料的莫尔异质结构工程可产生量子异质结构。利用最近证明的扭曲 vdW 异质外延，研究人员将构建 vdW 同质/异质结构，以实现出现在莫尔平带中的相关电子态。利用多尺度电子结构的理论和数学模型的输入，该项目将通过实验研究具有不寻常特性的多层二维超导系统，例如门可调转变温度和非常规配对对称性。将探索各种材料平台，包括扭曲双层石墨烯、扭曲三层石墨烯以及基于过渡金属二硫属化物的扭曲同质和异质结构。理论指导将是本研究不可或缺的一部分，因为材料平台和扭曲角度的选择多种多样，如果没有针对性的建模指导，仅靠实验是无法覆盖的。非常规超导性还可以促进拓扑超导体的开发和发现，从而可用于量子计算。由于底层量子态的拓扑性质，在拓扑超导系统中实现的量子位有望实现容错量子计算。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优势和更广泛的影响进行评估，被认为值得支持审查标准。

项目成果

Spectroscopic Signatures of Interlayer Coupling in Janus MoSSe/MoS 2 Heterostructures

Janus MoSSe/MoS 2 异质结构中层间耦合的光谱特征

• DOI: 10.1021/acsnano.1c03779
• 发表时间: 2021-09
• 期刊: ACS Nano
• 影响因子: 17.1
• 作者: Zhang, Kunyan;Guo, Yunfan;Larson, Daniel T.;Zhu, Ziyan;Fang, Shiang;Kaxiras, Efthimios;Kong, Jing;Huang, Shengxi
• 通讯作者: Huang, Shengxi

Dual-Gated Graphene Devices for Near-Field Nano-imaging

用于近场纳米成像的双门石墨烯器件

• DOI: 10.1021/acs.nanolett.0c04494
• 发表时间: 2021-02
• 期刊: Nano Letters
• 影响因子: 10.8
• 作者: Sunku, Sai S.;Halbertal, Dorri;Engelke, Rebecca;Yoo, Hyobin;Finney, Nathan R.;Curreli, Nicola;Ni, Guangxin;Tan, Cheng;McLeod, Alexander S.;Lo, Chiu Fan;et al
• 通讯作者: et al

Electrically Induced Dirac Fermions in Graphene Nanoribbons

石墨烯纳米带中的电感应狄拉克费米子

• DOI: 10.1021/acs.nanolett.1c03596
• 发表时间: 2021-11
• 期刊: Nano Letters
• 影响因子: 10.8
• 作者: Pizzochero, Michele;Tepliakov, Nikita V.;Mostofi, Arash A.;Kaxiras, Efthimios
• 通讯作者: Kaxiras, Efthimios

Correlated Insulating States and Transport Signature of Superconductivity in Twisted Trilayer Graphene Superlattices

扭曲三层石墨烯超晶格中超导性的相关绝缘态和输运特征

• DOI: 10.1103/physrevlett.127.166802
• 发表时间: 2021-10
• 期刊: Physical Review Letters
• 影响因子: 8.6
• 作者: Zhang, Xi;Tsai, Kan;Zhu, Ziyan;Ren, Wei;Luo, Yujie;Carr, Stephen;Luskin, Mitchell;Kaxiras, Efthimios;Wang, Ke
• 通讯作者: Wang, Ke

Lithium intercalation in MoS2 bilayers and implications for moiré flat bands

MoS2 双层中的锂嵌入及其对莫尔平带的影响

• DOI: 10.1103/physrevb.102.125424
• 发表时间: 2020-09
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Lu, Zheyu;Carr, Stephen;Larson, Daniel T.;Kaxiras, Efthimios
• 通讯作者: Kaxiras, Efthimios