Influence of interlayer interaction on the charge and lattice dynamics in layered transition-metal chalcogenides

层间相互作用对层状过渡金属硫属化物电荷和晶格动力学的影响

• 批准号: 440841111
• 负责人: Professorin Dr. Christine Kuntscher
• 金额: --
• 依托单位: Lehrstuhl für Experimentalphysik II
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/440841111?language=en
• 关键词: Influence; interlayer; interaction; charge; lattice

Layered transition-metal chalcogenides exhibit a plethora of interesting physical properties and exotic phases due to competing correlation effects and topology, such as charge-density wave, Mott insulator, superconductivity, antiferromagnetic topological insulator, Weyl semimetal, and ferromagnetic nodal-line semimetal. Furthermore, they provide an ideal platform for realizing atomically thin, van der Waals crystals with unique properties and excellent prospects for novel applications. For the understanding of the physical properties of these novel 2D crystals, the characterization and understanding of their bulk physical properties is crucial as a preliminary step and is the subject of this project.One key aspect determining the physical properties of two-dimensional, layered materials is the interlayer interaction. In particular, the variation of the interlayer interaction by changing the van der Waals interlayer spacing greatly affects their physical properties and induces phase transitions with emerging exotic phases. The systematic study and understanding of the influence of the interlayer interaction on the charge and lattice dynamics in layered transition-metal chalcogenides are the goal of this project. External pressure is the most effective way for tuning the interlayer spacing and hence the interlayer interaction in a controlled manner. Hence, external pressure will be applied within this project to systematically investigate the influence of interlayer interaction on the charge and lattice dynamics. By pressure-dependent infrared and Raman spectroscopy the charge and lattice dynamics can be studied while tuning the interlayer interaction in layered materials. This way, the pressure-induced electronic changes and phase transitions with emerging exotic electronic phases can be monitored and characterized in detail and with a high energy resolution.As model systems for this study several layered transition-metal chalcogenides are chosen, which on the one hand show interesting physical properties already at ambient pressure such as Weyl semimetal or magnetic topological phase, and on the other hand are very sensitive regarding pressure application.

由于相互竞争的相关效应和拓扑结构，层状过渡金属硫属化物表现出大量有趣的物理性质和奇异相，例如电荷密度波、莫特绝缘体、超导性、反铁磁拓扑绝缘体、韦尔半金属和铁磁节点线半金属。此外，它们还为实现原子级薄的范德华晶体提供了一个理想的平台，该晶体具有独特的性能和良好的新颖应用前景。为了了解这些新型二维晶体的物理性质，表征和理解其整体物理性质是至关重要的第一步，也是该项目的主题。确定二维层状材料的物理性质的一个关键方面是层间相互作用。特别是，通过改变范德华层间距来改变层间相互作用，极大地影响它们的物理性质，并诱导出现奇异相的相变。该项目的目标是系统研究和理解层间相互作用对层状过渡金属硫属化物中电荷和晶格动力学的影响。外部压力是以受控方式调节层间间距以及层间相互作用的最有效方法。因此，该项目将施加外部压力，系统地研究层间相互作用对电荷和晶格动力学的影响。通过压力相关的红外和拉曼光谱，可以研究电荷和晶格动力学，同时调整层状材料中的层间相互作用。通过这种方式，可以以高能量分辨率详细监测和表征压力引起的电子变化和新兴奇异电子相的相变。作为本研究的模型系统，选择了几种层状过渡金属硫属化物，一方面一方面在环境压力下已经表现出有趣的物理性质，例如外尔半金属或磁性拓扑相，另一方面对压力应用非常敏感。