Magnetic and electronic properties of graphene/MOFene superlattices

石墨烯/MOFene超晶格的磁和电子特性

• 批准号: 443405902
• 负责人: Professor Dr. Xinliang Feng
• 金额: --
• 依托单位: Professur für Theoretische Chemie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/443405902?language=en
• 关键词: Magnetic; electronic; properties; graphene; MOFene

In the first funding period we established the manufacturing of heterostructures (HS) made from vertical stacks of graphene and a crystalline two-dimensional polymer. We thoroughly characterized and understood its structure and electronic structure on ground of theory and experiment. We investigated in silico the corrugation of the HS presence and absence of typical substrates and the impact of the corrugation on the band structure. r In a 2DPI/graphene HS we were able to show strong intralayer charge transfer, enhancement of spectral features as well as first indications of a bandgap opening in graphene due to the interlayer interaction. Having established the general strategy to access the nanoscale electronic properties of such HS both theoretically and experimentally, we will focus on the more subtle magnetic interactions between 2D metal-organic frameworks, so-called MOFenes, and various graphene systems (graphene and gated Bernal-stacked bilayer graphene, gBLG) during the second funding period. These frameworks contain metal centers as nodal elements connected by organic ligands, and the metal centers carry charge and/or spin centers. MOFenes with a characteristic lattice thus will impose a charge/magnetic superlattice of the same structure on any interfaced 2D material, such as graphene or gBLG. In such HSs we will be able to investigate effects of lattice topology and different metal centers on the resulting magnetism of the HS. We will explore magnetic and electronic intralayer coupling in the MOFenes of honeycomb, kagome and rhombic lattice topology both experimentally and theoretically. This allows to tune the intra versus interlayer magnetic coupling and thus the resulting macroscopic magnetic properties. Most intriguingly, we will be able to investigate the impact of magnetism and intralayer spin-orbit coupling of the MOFene on the intricate correlated states we recently identified in gBLG near its tunable van-Hove singularity. A central goal of these investigations is the understanding of superlattice effects of different topology. While for all lattices ferromagnetic and antiferromagnetic ordering of the magnetic centers is possible, in the kagome lattice spin frustration should either should give ferromagnetic ordering or a spin liquid. As interactions can be tuned by the choice of magnetic centers and ligands, such intriguing 2D spin-liquid systems will become feasible. This proposal employs a rich range of experimental and theoretical methods, including advanced material transfer techniques, quantum transport, scanning near-field microscopy, nanoscale scanning spectroscopy, orthogonal tight-binding hamiltonians, density-functional theory (DFT), DFT based tight-binding, and quasiparticle methods.

在第一个资金期间，我们建立了由石墨烯和晶体二维聚合物制成的异质结构（HS）的制造。我们在理论和实验的基础上彻底表征并理解了其结构和电子结构。 我们在计算机中研究了HS存在和典型底物的不存在以及波纹对带结构的影响。在2DPI/石墨烯HS中，我们能够显示出强大的内部电荷转移，频谱特征的增强以及由于层相互作用而在石墨烯中开放带频率的第一指示。在建立了在理论和实验上访问此类HS的纳米级电子特性的一般策略之后，我们将重点关注第二次拟合期间2D金属有机框架，所谓的Mofenes和各种石墨烯系统（类似的杂种和甲壳叠层的毛线纤维，GBLG）之间更微妙的磁相互作用。这些框架包含金属中心作为由有机配体连接的淋巴结元件，金属中心带有电荷和/或自旋中心。因此，具有特征晶格的Mofenes将在任何接口的2D材料（例如石墨烯或GBLG）上施加相同结构的电荷/磁性超级晶格。在这样的HSS中，我们将能够研究晶格拓扑和不同金属中心对HS磁性的影响。我们将在实验和理论上探索蜂窝，kagome和菱形晶状体拓扑的磁性和电子内部耦合。这允许调整内部与层间磁耦合以及所得的宏观磁性特性。最有趣的是，我们将能够研究Mofene的磁性和内旋转型轨道耦合对我们最近在GBLG中在其可调的Van-Hove奇异性附近发现的复杂相关状态的影响。这些调查的一个核心目的是了解不同拓扑的超晶格效应。尽管对于所有晶格，磁心中心的铁磁和抗铁磁序列都是可能的，但在Kagome晶格旋转挫败感中，应进行铁磁体订购或自旋液体。由于可以通过选择磁心中心和配体来调整相互作用，因此这种有趣的2D自旋液体系统将变得可行。该提案采用了丰富的实验和理论方法，包括先进的材料转移技术，量子传输，扫描近场显微镜，纳米级扫描光谱，正交紧密结合汉密尔顿，密度功能性理论（DFT），基于DFT的紧密结合和Quasiparticle方法。