Organic Control of Topological Surface States for THz Logic

拓扑绝缘体是一类特殊的材料，由于能带反转而表现出导电的表面态。这种表面态具有显著的性质，包括自旋动量锁定和狄拉克费米子的近无损输运。这些材料在计算、传感和THz通信方面有着丰富的应用。拓扑表面状态可以通过有机掺杂剂的使用进行主动控制，为通信，传感和量子技术提供了一条通往低损耗，高速电子产品的路线。首先，将与利兹大学合作开发融合拓扑绝缘体和有机半导体的混合材料，并在格拉斯哥的开尔文纳米表征中心和SuperSTEM使用电子显微镜进行分析。我们将建立生产高绝缘TI材料BiSbTe的生长工艺，该材料涂覆有C60的高结晶层以及诸如铜酞菁的有机分子。在第二阶段，我们将分析这些材料的表面状态，寻找拓扑表面状态及其有机物修饰的特征。在第三阶段，我们将把这些材料制成纳米天线，以便使用电子能量损失谱分析表面态的等离子体特性。新颖性在项目结束时，我们将牢固地建立一个新的范例，用于工程拓扑绝缘体的表面态。到目前为止，由于沉积的困难，有机半导体和TI还没有集成到单个器件中，并且不能用于在现实器件中修饰表面状态。这个问题现在已经通过利兹大学的罗伊斯沉积系统得到解决。通过结合材料专业知识的利兹与世界领先的电子显微镜在格拉斯哥，我们可以探索这种全新的混合材料类，并开发新的设备概念从them. align和StrategyThis项目旨在减少能源消耗的通信和计算基础设施，利用极低损耗的传输制度在有源器件。这是通过开发利用新型凝聚态物理学的先进功能材料来实现的。这些器件最终将应用于光子电路，并有可能应用于集成光子学和自旋电子学的器件中。CollaborationsThe project is supervised by Dr Timothy Moorsom，Lecturer in Advanced Materials and皇家工程学院研究员，以及Dr Donald MacLaren，Senior Lecturer，in the Materials and Condensed Matter Physics group.该项目涉及等离子体应用的拓扑-绝缘体-有机混合器件的制造和表征。他们将利用詹姆斯瓦特纳米加工中心的洁净室设施，以及开尔文纳米表征中心的电子显微镜设备，发展尖端技术与国家的最先进的设备。除了在格拉斯哥大学工作外，他们还将利用利兹大学亨利罗伊斯研究所的多功能分子束外延来生长新型拓扑材料。还将有机会参加国家和国际设施的合作实验，如卢瑟福·阿普尔顿实验室、苏黎世的保罗·谢勒研究所和巴塞罗那的ALBA同步加速器。

SummaryTopological Insulators are a special class of materials which exhibit a conducting surface state as a consequence of band inversion. This surface state has remarkable properties, including spin-momentum locking and near lossless transport of Dirac fermions. These materials have a wealth of applications in computing, sensing and THz communications. Topological surface states can be actively controlled through the use of organic dopants, providing a route towards low-loss, high speed electronics for communications, sensing and quantum technologies.ObjectivesThe project will proceed in three stages. Firstly, hybrid materials fusing topological insulators and organic semi-conductors will be developed through collaboration with Leeds University, and analysed using the electron microscopes in the Kelvin Nano-Characterisation Centre at Glasgow and at SuperSTEM. We will establish growth processes to produce the highly insulating TI material, BiSbTe, coated with highly crystalline layers of C60, as well as organic molecules such as Cu-Pthalocyanine. In the second phase, we will analyse the surface states of these materials, looking for signatures of topological surface states and their modification by organics. In the third phase, we will pattern these materials into nano-antennae, in order to analyse the plasmonic characteristics of the surface states using electron energy loss spectroscopy.NoveltyBy the end of the project, we will have firmly established a new paradigm for engineering the surface states of topological insulators. Until now, organic semiconductors and TIs have not been integrated into a single device due to the difficulty of deposition, and could not be used to modify surface states in realistic devices. This has now been solved by the creation of the Royce Deposition System at the University of Leeds. By combining the materials expertise of Leeds with world leading electron microscopes at Glasgow, we can explore this entirely novel class of hybrid materials and develop new device concepts from them.Alignment and StrategyThis project aims to reduce energy consumption of communication and computational infrastructure by utilising extremely low-loss transport regimes in active devices. This is achieved through the development of advanced functional materials that take advantage of novel condensed matter physics. These devices will ultimately be applied in photonic circuits and potentially in devices that integrate photonics and spintronics.CollaborationsThe project is supervised by Dr Timothy Moorsom, Lecturer in Advanced Materials and Royal Academy of Engineering Fellow, and Dr Donald MacLaren, Senior Lecturer, in the Materials and Condensed Matter Physics group. The project involves the fabrication and characterisation of topological-insulator-organic hybrid devices for plasmonic applications. They will utilise the James Watt Nanofabrication Centre cleanroom facilities as well as the Kelvin Nanocharacterisation Centre's electron microscopy equipment, developing cutting edge skills with state-of-the-art equipment. In addition to work at the University of Glasgow, they will utilise the Henry Royce Institute's multifunctional MBE, at the University of Leeds, to grow novel topological materials. There will also be opportunities to take part in collaborative experiments at national and international facilities suchas the Rutherford Appleton Laboratory, the Paul Scherrer Institute in Zurich and the ALBA synchrotron in Barcelona.