过去几年，针对拓扑电子材料中新奇量子态研究已成为凝聚态物理学科发展最快的研究领域之一，产生许多新概念、新物理，并展现出极其诱人的应用前景。本项目将结合最新能带理论计算结果(参看最近的连续3篇Nature，预言了几千种拓扑电子材料)，利用我们多年合成铊基化合物经验，在制备出高品质单晶样品的基础上，通过对其电子能带、磁阻、霍尔效应和热电势等物理性质的系统观测，旨在发现2-3类新型铊基拓扑材料（如拓扑绝缘体、Dirac/Weyl半金属）；同时采用元素替代、原子插层、外加压力等手段调控其电子结构，关注自旋-轨道耦合作用，寻找可能存在的拓扑相变、以及新型的拓扑超导体。其结果不仅会加深对拓扑物理的认识、丰富拓扑材料系统，而且会为拓扑电子材料的应用提供更多选项。

In the past few years, the study of novel quantum states in the topological electronic materials has become one of the fastest growing fields in condensed matter physics. In this process, many new concepts have been proposed and many new properties been revealed, making them attractive both in fundamental research and application. This project will carry out the research on thallium-based materials, basing on the results of the latest band calculation (Three Nature papers, thousands of topological materials) and our experimental experience. The electronic band structure and the physical properties, such as magneto-resistance, Hall and thermopower effect, and so on, will be investigated systematically, to reveal the intrinsic properties of these quantum states. Two or three new thallium-based topological electronic materials will be confirmed experimentally (such as topological insulators, Dirac/ Weyl semi-metals). Then, their band structure, especially the spin-orbit coupling will be modulated, by means of chemical doping, atom intercalation, applying pressure, and so on, looking for possible topological phase transitions and new topological superconductors. All these results will not only help to understand the physics of these novel quantum states and enrich the systems of the topological materials, but also provide more options for the application.