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

自从最初的理论预测以来，三维拓扑绝缘体因其众多的特性而引起了人们的极大关注，从新颖的量子现象到自旋电子学的应用。许多理论预测的现象还有待于他们的实验观察，这是因为对体积电导率大大降低的样品以及具有超清洁表面和界面的薄膜和器件的强烈需求。在我们的初步工作中，我们可以证明，我们能够制备出具有所需纯度和表面清洁度的Bi2Te3薄膜，直接测量拓扑表面态的电导率，并在不影响其分散性和电荷填充的情况下对其进行封顶和保护。这是使用全原位/超高真空工艺实现的。在这个项目中，我们现在准备迎接挑战，制备这种类型的拓扑绝缘体与超导和铁磁体的超净界面，并测量它们的性能，从而利用我们的专业知识来排列高质量的超导和氧化物铁磁体薄膜。

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.