新型拓扑材料设计与拓扑有序态的基础理论研究

项目名称： 新型拓扑材料设计与拓扑有序态的基础理论研究

项目编号： No.11204359

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 物理学I

项目作者： 徐刚

作者单位： 中国科学院物理研究所

项目金额： 24万元

中文摘要： 拓扑绝缘体是一类具有非平庸拓扑性质(Z2)的新型量子材料，其内部绝缘，但在表面上存在着一种无能隙的、自旋与动量锁定的狄拉克型能带结构。近年来，随着对拓扑绝缘体的深入研究，许多新奇的拓扑物性被预言和发现，如量子反常霍尔效应、拓扑金属、磁单极、拓扑超导电性和Majorana费米子等，它们共同够成了庞大的拓扑家族。作为一种全新的量子物态，拓扑材料因其丰富奇特的电子特性以及在未来自旋电子器件和容错量子计算机中的潜在应用价值，在世界范围内取得了快速发展，并成为凝聚态物理中的一个热点领域。本研究项目拟发展一套计算拓扑数的普适性方法；探索压力、磁场、元素替代等对拓扑序的调制，进而深入理解拓扑序与其它量子有序态之间合作与竞争的物理机制；利用不需要人为参数的第一性原理计算，集中研究4d/5d过渡金属化合物，探寻和设计可能的拓扑新材料，为材料合成和实验研究提供理论指导和依据。

中文关键词： 量子反常霍尔效应；Weyl费米子；拓扑超导；拓扑晶体绝缘体；第一性原理计算

英文摘要： Topological insulator (TI) is a novel material characterized by the non-trivial topological order. It behaves as an insulator in its interior or bulk, while possessing a gapless and Dirac-type metallic surface state in which spin and orbital is locked. With the development of TI, many new topological states are predicted and identified, such as quantized anomalous Hall effect (QAHE), topological metal, magnetic monopole, topological superconductor (TSC) and Majorana fermions. All of them can be classified as the non-trivial topological phenomena and realized in topological materials. As new quantum matter states, many topological phenomena have attracted tremendous interests not only because of their fascinating electronic properties, but also the great valuable applications in future spintronic devices designing and fault-tolerant quantum computers. In this project, we will develop a new universal algorithm to calculate the topological order for both cases with or without time-reversal symmetry. Using this method, we intend to study the evolution of topological order with pressure, magnetic field and element substitution, and further explore the interactions between topological order and other quantum ordered states, such as ferromagnetic state and superconducting. Finally, we will focus on 4d/5d transition met

英文关键词： Quantum anomalous Hall effect (QAHE)；Weyl Fermion；Topological superconductivity (TSC)；Topological crystalline insulator (TCI)；The first principles calculations