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题名	基于角分辨光电子能谱的真空控制系统开发与狄拉克节线半金属的研究
作者	洪光昊
文献子类	硕士
导师	柳仲楷
关键词	角分辨光电子能谱 ARPES 真空控制系统 Vacuum control system 狄拉克节线半金属 Dirac line-node semimetal ZrSiS材料 ZrSiS material
其他题名	Development of Vacuum Control System and Study on Dirac Line-node Semimetal Based on Angle-resolved Photoemission Spectroscopy
英文摘要	拓扑量子材料是过去十年中凝聚态物理领域的研究重点之一，拓扑绝缘体和拓扑半金属都相继被实验证实。狄拉克节线半金属是目前凝聚态物理领域的前沿研究话题。目前拓扑量子材料的发现主要依赖于角分辨光电子能谱技术，该技术是探测固体能带结构最直接的实验手段。所以对于狄拉克节线半金属能带结构的研究，角分辨光电子能谱依然是最直接的选择。同时，超高真空系统的自动化实现，可以有效地延长样品的采集时间，提高实验系统的稳定性，并且可以针对不同的要求来定制相关的自动化控制功能，因此需要开发出独立的真空控制系统。由此，本文主要围绕角分辨光电子能谱仪的真空控制系统开发和该仪器对于狄拉克节线半金属材料的探测展开，得到了以下的结果： （1）真空控制系统开发方案的提出与具体实施 角分辨光电子能谱的真空控制系统开发遵循了自动化系统的标准开发流程。首先，通过对控制系统不同环节进行多种方案的测试比较，确定了以PLC为核心、辅以工业触控屏和LabVIEW的控制系统开发方案。具体实施过程中，在真空控制逻辑的基础上，利用工业触控屏和PLC的组合实现了真空系统的完整控制与自动保护；在真空状态监控的需求下，利用LabVIEW和PLC的这对组合实现了对整个实验系统的真空状态的采集。最后，还利用LabVIEW实现了空间分辨光电子能谱仪回转支承部分的电机控制，并提出了可行的真空控制与运动控制互锁联动方案。 （2）ZrSiS材料体态和表面态信息与其狄拉克节线的存在 利用基于同步辐射的高分辨角分辨光电子能谱，我们系统测量了沿着 (001)面解离的狄拉克节线半金属材料ZrSiS的电子能带结构。高质量的单晶样品带来高质量的能带数据，通过实验数据与该材料的第一性原理计算对比发现，二者具有很好的一致性，由此我们初步区分出了该材料中的体态和表面态信息。进一步地，根据光子能量依赖实验结果，我们再次确认了体态和表面态信息，并通过追踪狄拉克点的位置，证实了狄拉克节线形成于布里渊区边界的X-R-X方向，与理论预言和计算相符合。最后利用原位表面钾掺杂的方法来调控化合物电子能带结构，我们清楚地观察到了体态和表面态的不同演化，并且证明了狄拉克节线的稳定性。; Topological quantum materials are one of the research focuses in the field of condensed matter physics in the past decade. Both topological insulators and topological semimetals have been experimentally verified. The Dirac line-node semimetals are currently the forefront research topic in condensed matter physics. At present, the discovery of topological quantum materials mainly depends on the angle-resolved photoelectron spectroscopy (ARPES) technology, which is the most direct experimental method to detect the solid energy band structure. So for the study on electronic structure of Dirac line-node semimetal, ARPES is still the directly choice. At the same time, the automation of the ultra-high vacuum system can effectively prolong the sample collection time, improve the stability of the experimental system, and can customize the relevant automation control functions for different requirements. Therefore, an independent vacuum control system needs to be developed. Therefore, this article mainly focuses on the development of the vacuum control system of the ARPES and study on Dirac line node semimetal by ARPES detection. The following results are obtained: (1) Development and implementation of vacuum control system The development of ARPES vacuum control systems follows the standard development process of automation systems. Firstly, through testing and comparing various schemes of different parts of the control system, we confirmed the control system schemes with PLC as the core, industrial touch screen and LabVIEW as the auxiliary. In the specific implementation process, following the vacuum control logic, the complete control and automatic protection of the vacuum system was realized using the combination of an industrial touch screen and a PLC; under the requirement of vacuum status monitoring, a combination of LabVIEW and PLC was used to achieve the vacuum status collection. Finally, we used LabVIEW to realize a motor control of the slewing bearing in the Nano-ARPES, and proposed a feasible interlocking scheme between the vacuum control and the motion control. (2) The bulk states, surface states and the existence of Dirac line node in ZrSiS We systematically measured the electronic structure of Dirac line-node semimetal ZrSiS on its (001) surface by using ARPES based on synchrotron radiation source. The experimental results agree nicely with the ab-initio calculations, so that we can distinguish the bulk states and surface states elementary. Furthermore, a series of photon-energy-dependent measurements confirm the bulk states and surface states again while proving the existence of Dirac line node along the X-R direction which is located at Brillouin zone boundary by tracking the positions of the Dirac points. Finally, We clearly observe the different evolutions of the bulk and surface states by using surface doping method which can manipulate the electronic structure of the compound，and prove the robustness of the Dirac line node.
学科主题	凝聚态物理
内容类型	学位论文
源URL	[http://ir.siom.ac.cn/handle/181231/31123]
专题	中国科学院上海光学精密机械研究所
作者单位	中国科学院上海光学精密机械研究所
推荐引用方式 GB/T 7714	洪光昊. 基于角分辨光电子能谱的真空控制系统开发与狄拉克节线半金属的研究[D].

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