Advanced Topological materials for Plasmonics

等离子体动力学涉及将光限制在纳米级结构中，作为电子的集体激发。开发基于等离子体的下一代器件在通信、高速计算和量子光学等领域具有重要的技术应用。特别令人感兴趣的是表面等离子激元极化，它以表面波的形式传播，对其局部环境特别敏感，使其在传感器和通信中非常有用。通常，等离子体超材料是通过在一层高导电性金属（如金）上蚀刻图案而产生的。周期模式允许关键参数，如介电常数，被操纵并产生在自然界中看不到的效果。近年来，在拓扑绝缘体中发现了一种新的表面等离子体。这些合金具有具有独特性能的拓扑表面状态。这些狄拉克等离子体模式具有较低的损耗和自旋与动量之间的耦合，在自旋电子学和量子计算中可能具有重要的应用。这些模式可以使用某些表面涂层和掺杂剂，包括有机分子来操纵。本项目将开发一种从拓扑绝缘体制备等离子体超材料的新方法。我们将使用有机涂层和离子掺杂的组合来创建拓扑表面状态间隙的区域，而不是使用传统的光刻技术在材料中创建周期性图案。它不是作为真空和导电表面区域存在，而是作为不同拓扑特征区域之间的对比而存在。除了在一类奇异材料中探索新的等离子体物理外，该项目还将开发开发超材料的新技术，这将对该领域产生重大影响。成功的候选人将使用亨利罗伊斯沉积系统开发这些材料，这是利兹大学的世界领先系统，并将与曼彻斯特大学合作使用pNAME系统开发图像化方法。他们将发展一系列光刻和材料生长方面的可转移技能，以及对电子显微镜、电子、光学和太赫兹表征技术的理解。

Plasmonics involves confining light to nanoscale structures as a collective excitation of electrons. Developing next generation devices based on plasmonics has important technological applications in communications, high-speed computing and quantum optics. Of particular interest are surface plasmon polaritons, which propagate as a surface wave and are particularly sensitive to their local environment, making them useful in sensors and communications. Typically, plasmonic meta-materials are created by etching patterns into a layer of highly conducting metal, such as gold. The periodic pattern allows critical parameters, such as the permittivity, to be manipulated and produce effects not seen in nature. Recently, a new form of surface plasmon was observed in topological insulators. These are alloys that possess topological surface states with unique properties. These Dirac plasmon modes exhibit lower losses, and coupling between spin and momentum which may have important applications in spintronics and quantum computing. These modes can be manipulated using certain surface coatings and dopants, including organic molecules. This project will develop a new method for creating plasmonic meta-materials from topological insulators. Rather than using conventional lithography to create periodic patterns in the material, we will use a combination of organic coatings and ion doping to create regions where the topological surface state is gapped. Instead of the pattern existing as regions of vacuum and conducting surface, it exists as a contrast between regions with different topological character. As well as exploring novel plasmon physics in an exotic class of materials, this project will also develop new techniques for developing meta-materials, which will have a significant impact on the field. The successful candidate will develop these materials using the Henry Royce Deposition System, a world leading system at the University of Leeds, and will develop the patterning methods in collaboration with the University of Manchester using the pNAME system. They will develop a range of transferable skills in lithography and materials growth, as well as an understanding of electron microscopy, electronic, optical and terahertz characterisation techniques.