关联拓扑电子体系宏观量子特性及材料探索研究

项目名称： 关联拓扑电子体系宏观量子特性及材料探索研究

项目编号： No.11204384

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： 吴东

作者单位： 中山大学

项目金额： 30万元

中文摘要： 关联拓扑电子体系呈现出新奇的量子物态，主要包括关联拓扑能带绝缘体、拓扑莫特绝缘体或拓扑超导体。由于涉及到复杂的多体相互作用及相对论效应，关联拓扑电子体系的理论和实验研究存在诸多困难。特别在实验上，高品质拓扑关联电子体系的缺乏，严重阻碍了人们对关联拓扑电子体系新奇量子现象的进一步研究。基于此，我们提出《关联拓扑电子体系的宏观量子态及材料探索研究》这一课题，旨在通过材料设计，选择合成周期短、组分比例易于控制的块体材料而非薄膜作为优先合成对象，采用固溶、提拉、水平温度梯度、布里奇曼坩埚下降等材料合成技术，围绕元素序数较高、关联效应较强的d、f电子体系化合物进行材料设计和探索研究。同时，通过高精确量组分调控或掺杂工程，结合多重物性的表征分析工作，发掘深层次的自旋-轨道耦合与电子关联的相互作用关系，以及它们共同作用下体系呈现的最终拓扑量子态特性。

中文关键词： 磁性半导体；磁阻；自旋轨道耦合；光致电流效应；强关联效应

英文摘要： Recent theory and experiment have revealed that strong spin-orbit coupling (SOC) can allow a nontrivial topology of the electron bands, leading to a distinct phase of matter, the topological band insulator. Then, the interplay of interaction and topology has recently proposed a rich avenue for the discovery of new phases of matter too, such as topological Mott insulator(TMI) and topological superconductor. However, in case of complicated manybody interaction and relativistic effect, it was quite difficult for both theory and experiment developing in this new area. It could be hardly found any material showing thoese new phases for a long time. On the other hand, as SOC scales with atomic number as Z*4, strong SOC and electron correlation may be expected in compounds involving some d or f electrons. Especially in 5d or rare-earth element systems, electron-correlating effects are often of weak or intermediate strength, making them perhaps competitive with those SOC and band structure effects. Owing to the surge of activity in GdPtBi and Ir-based transition-metal system, we choose "New correlated topological materials and their characteristic macroscopic quantum phases" as our research title. we will begin with new compounds design involving high Z elements. Then, synthesizing their bulk crystals by different tec

英文关键词： magnetic semiconductor；magnetoresistance；spin-orbit coupling；photoelectric effect；strong electron correlation