拓扑绝缘体异质结中界面电子结构调控的研究

项目名称： 拓扑绝缘体异质结中界面电子结构调控的研究

项目编号： No.11304206

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 田晓庆

作者单位： 深圳大学

项目金额： 25万元

中文摘要： 拓扑绝缘体是制备新一代低功耗纳米电子和自旋电子器件的重要材料之一。在拓扑绝缘体器件的应用中，将不可避免地与其他材料形成异质结，但其异质结的电子结构及物性尚未被完全揭示，这将限制对拓扑绝缘体器件的设计、制备及应用。针对上述问题，本项目用第一性原理计算方法研究拓扑绝缘体（硒化铋、碲化铋、碲化锑）与三种电子功能材料异质结的电子结构及物性。首先研究拓扑绝缘体/石墨烯异质结，计算外加电场、碱金属、磁性杂质及晶格缺陷对这两种材料的狄拉克费米子的影响和调控；其次研究拓扑绝缘体/金属电极异质结，计算电接触势垒，界面拓扑态的有效质量, 迁移率，为拓扑绝缘体寻找合适的欧姆电极；最后研究拓扑绝缘体/磁性材料异质结，探索铁磁及反铁磁材料对拓扑绝缘体拓扑态的能量-动量色散关系及自旋分辨特性的调控。本项目的研究结果将加深我们对拓扑绝缘体物理特性的认识，为拓扑绝缘体在电子学及自旋电子学领域的应用提供理论依据和参考方法。

中文关键词： 拓扑绝缘体；石墨烯；第一性原理计算；黑磷；过渡金属二硫属化物

英文摘要： Topological insulator is one of the most important materials for fabricating nanoelectronic and spintronic devices. While being applied to devices, topological insulators will inevitably form heterojunctions with other materials. However, the electronic structures and physical properties of topological insulator heterojunctions have not been clearly revealed yet, which will restrict the design, fabrication and application of topological insulator devices. To clarify these issues, we will study the interfacial electronic structures and physical properties of heterojunctions composed of topological insulators (bismuth selenide, bismuth telluride and antimony telluride ) and other three classes of electronic functional materials. First, we will study the topological insulators/graphene heterojunction. We will investigate the modulation of Dirac fermions of the interface by external electric field, alkali metal, magnetic impurity and crystal defects. Second, we will study the topological insulators/metal electrodes heterojunctions. We will calculate the contact barrier, effective mass and mobility of topological surface state to find alternative Ohmic contacts. Finally, we will study the topological insulators/magnetic materials heterojunctions. We will explore the modulation of energy-momentum dispersion and spin

英文关键词： Topological insulators；Graphene；First-principles calculations；Phosphorene；Transition-metal dichalcogenides