Atomistic theory of impurity and substrate effects in graphene

石墨烯中杂质和底物效应的原子理论

• 批准号: 173546874
• 负责人: Professor Dr. Alexander Lichtenstein
• 金额: --
• 依托单位: I. Institut für Theoretische Physik
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/173546874?language=en
• 关键词: Atomistic; theory; impurity; substrate; effects

Being a two-dimensional Dirac material, graphene offers unique possibilities for manipulating its electronic properties by interfacing and adsorbates. It is thus our goal to provide a first-principles based theory which can explain and predict the response of the electron systemin graphene to substrates and adsorbates and which will be linked to experiments and low-energy models. We will explore how chemical binding to adsorbates can be controlled by external charge doping and how ordered adsorbate phases leading to excitation gaps at the Dirac point can emergefor graphene in realistic environments. We will study transport and spectral properties of realistically disordered graphene and explain the evolution of optical properties of graphene under hydrogenation and fluorination. In transition metal and rare earth adatoms on graphene electronic interactions are decisive and we aim to understand the chemistry of graphene and adatoms in presence of electron correlations and substrates. We will predict which adatom / substrate combinations are best suited to realize a Kondo effect as well as magnetism in graphene. Already in pristine graphene mono-, bi- or trilayers electron-electron interactions are special due to the coexistence of strong local and non-local terms and can lead to many-body instabilities. It is therefore our goal to study how Coulomb interactions and related many-body instabilities in graphene-based materials can be controlled by interfacing with substrates and doping. Finally, interfacing of graphene with layered insulators can be used to build vertical graphene transistors and to manipulate the low energy electronic structure by moiré effects. We thus aim to build a first-principles theory of superlattice effects, in-plane and vertical electron transport in these graphene hybrid structures.

作为一种二维狄拉克材料，石墨烯提供了独特的可能性，操纵其电子性质的界面和吸附。因此，我们的目标是提供一个基于第一性原理的理论，可以解释和预测的电子系统在石墨烯衬底和吸附物的响应，这将与实验和低能模型。我们将探讨如何通过外部电荷掺杂来控制与吸附物的化学结合，以及如何在现实环境中为石墨烯出现导致狄拉克点激发隙的有序吸附物相。我们将研究实际无序石墨烯的输运和光谱性质，并解释氢化和氢化下石墨烯光学性质的演变。在石墨烯上的过渡金属和稀土吸附原子中，电子相互作用是决定性的，我们的目标是了解石墨烯和吸附原子在电子相关性和衬底存在下的化学。我们将预测哪种吸附原子/基底组合最适合实现近藤效应以及石墨烯的磁性。在原始石墨烯单层、双层或三层中，由于强局域和非局域项的共存，电子-电子相互作用是特殊的，并且可能导致多体不稳定性。因此，我们的目标是研究如何库仑相互作用和相关的石墨烯基材料的多体不稳定性可以通过与衬底和掺杂的接口控制。最后，石墨烯与层状绝缘体的界面可以用于构建垂直石墨烯晶体管，并通过莫尔效应操纵低能电子结构。因此，我们的目标是建立一个第一性原理理论的超晶格效应，在这些石墨烯混合结构的平面和垂直电子输运。