强磁场下强自旋轨道电子材料的多量子态与调控研究

项目名称： 强磁场下强自旋轨道电子材料的多量子态与调控研究

项目编号： No.U1432251

项目类型： 联合基金项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 田明亮

作者单位： 中国科学院合肥物质科学研究院

项目金额： 270万元

中文摘要： 在4d/5d关联电子材料中，许多奇特物性是由强自旋轨道相互作用导致的，包括莫特绝缘体、手征自旋液体、拓扑半金属以及宽带隙拓扑绝缘体等。强磁场作为一种极端实验条件在很多领域显露出它的重要作用，比方说～30T的磁场在能量上为几个毫电子伏，已经不再是一个可忽略的微扰，能够很有效地调控各种竞争能量之间的平衡关系，诱导出新的量子序，从而导致新现象。在过去几十年的强关联研究中，人们主要强调了3d元素的作用而对自旋轨道作用以及该作用所诱导的基本相关效应大多被忽略了。本项目拟开展：（1）5d铱化物中的奇异量子现象与量子调控机制；（2）新型宽带拓扑绝缘体及由关结构中的新量子态与量子输运研究；（3）过渡金属氧化物薄膜和人工结构中序竞争及界面效应研究。目标就是通过强磁场等方法实现对电荷、自旋、轨道等量子有序态的调控，使之出现全新的物质状态，从而呈现出新现象、新物理，并推动最前沿的基础材料研究的发展。

中文关键词： 强关联电子体系；强磁场；自旋轨道耦合；人工二维异质界面；过渡金属氧化物

英文摘要： In 4d/5d strongly correlated electron materials, many exotic physical properties were closely related to the strong spin-orbital interactions, including Mott insulator, chiral spin liquids, topological semimetals and topological insulators and so on. High magnetic field experimental condition has played an important role in wide fields, especially in 5d electronic system with strong spin-orbital interactions. For instance, a 30T high magnetic field amounts to an energy level of~ meV is no longer a small perturbative influence in materials based upon heavy transition elements, but comparable to those critical to the band topology in the 4d/5d materials, and this energy is expected to readily tip the balance between the competing energies, inducing novel phenomena never seen in other materials. In the past a few decades, most of the work gave rise to the pervasive emphasis on the 3d-elements in both basic and applied research, the phenomenology of the spin-orbital interaction and its fundamental consequences on material properties has been neglected until recently. In his proposal, we will turn our attention on three aspects: (1) Modulation of quantum phase and the exotic properties in 5d irridates; (2) New phase and quantum transport behavior in novel topological insulators under high magnetic fields; (3) Competition of multiple quantum ordering and interfacial effect in transition metal multilayers and artificial two dimensional heterogeneous interface. Our target is to investigate the possible novel phenomena in these systems induced by high magnetic field through effectively tuning the relative strengths of the spin orbital interaction, on-site Coulomb interactions and the crystal fields.

英文关键词： strongly correlated electron system;high magnetic field;spin orbital coupling;Artificial 2D heterogeneous interfaces;Transition metal oxides