Interfacing superconductors and ferromagnets with topological insulators using all in-situ/ultra high vacuum processes

• Applicant: Professor Dr. Liu Hao Tjeng
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2016 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 314905363

Since its initial theoretical prediction, three-dimensional topological insulators have attracted intense attention for its multitude features, ranging from novel quantum phenomena to spintronics applications. Much of the theoretically predicted phenomena await their experimental observations due to the strong need for samples with much reduced bulk conductivity as well as films and devices with ultra-clean surfaces and interfaces. In our preliminary work, we can show that we are able to prepare Bi2Te3 films with the required purity and surface cleanliness, to measure directly the conductivity of the topological surface states, and to cap and protect them without affecting their dispersions nor their charge filling. This has been achieved using an all in-situ/ultra high vacuum process. In this project, we are now ready to take up the challenge to prepare ultra clean interfaces of this type of topological insulators with superconductors and ferromagnets and to measure their properties, thereby making also use of our expertise to row high quality films of superconductors and oxide ferromagnets.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1666: Topological Insulators: Materials - Fundamental Properties - Devices