新型二维层状材料的拓扑量子态研究

新型二维层状材料（石墨烯、硅烯等）和能带结构非平庸的体系（Chern绝缘体、Z2拓扑绝缘体以及拓扑超导体等）是当前凝聚态领域的两大热点。二维体系如石墨烯、硅烯因具有Dirac电子行为以及优异的物理性能等而倍受关注。拓扑量子态在自旋电子学以及拓扑量子计算有着潜在的重要应用。本项目旨在如何最大限度地结合新型二维材料以及拓扑量子态的优势，即在二维材料体系中找到以及设计出环境友好且易实现上述拓扑量子态的具体物理途径和材料体系。具体如下：研究如何在二维层状材料中找到或设计出具有大的体能隙的Chern绝缘体、Z2拓扑绝缘体和具有较高Tc的拓扑超导体；研究如何有效的利用电场、磁场、光场、应力（赝磁场）、化学修饰、缺陷以及量子限域等手段调控上述拓扑量子态的电子性质和输运性质；探讨引入相互作用，考虑关联效应对这些拓扑量子态的影响。上述研究将为低耗散的量子器件以及容错的拓扑量子计算提供候选材料和理论指导。

Novel two-dimensional layered materials (such as graphene and silicene etc.) and non-trivial band structure systems (like Chern insulators, Z2 topological insulators as well as topological superconductors) are two hotspots in the condensed matter field. Graphene and silicene have drawn numerous attentions due to their unique Dirac fermion behaviors, high mobility, and excellent mechanic properties. Topological quantum states have potential applications of significance in spintronics and topological quantum computation. The project aims at how to combine the advantage of the both with a maximum degree, i.e. in the two-dimensional layered materials how to find and design the explicit material systems and physical paths in or by which the above topological quantum states can be realized environmental friendly and steadily. Specifically, the project includes the following several parts: (1) Study how to discover and design Chern insulators, Z2 topological insulators and other novel topological quantum states with large bulk gaps as well as topological superconductors with high Tc. (2) Research how to tune the electronic properties and transport properties of the above topological quantum states in the two-dimensional layered materials efficiently and accurately via electronic field, magnetic field, photonic field, strain (pseudo-magnetic field), chemical modifications, defects and quantum confinement etc. (3) Discuss deeply the effect of correlation on these topological quantum states when introducing interactions. These efforts will provide the better candidate materials and theoretical guides for the low-power dissipation quantum devices and the fault-tolerant topological quantum computations.