论文标题
拓扑绝缘体中接近诱导的超导性
Proximity induced superconductivity in a topological insulator
论文作者
论文摘要
将拓扑绝缘子（TI）与$ S $ - 波超导体（SC）接口是一个有前途的材料平台，可以实现实现拓扑超导体的可能性，可以通过该导体，可以通过该平台进行设计。在我们对NB和BI $ _2 $ te $ _3 $之间的原型SC/TI接口的计算研究中，我们确定了该潜在的Majorana材料平台的好处和可能的瓶颈。将NB与Ti膜接触会导致从SC到Ti的电荷掺杂，从而将费米水平转移到Ti传导带。对于厚的Ti膜，这会导致带弯曲导致界面处的琐碎Ti量子孔状态的种群。在超导状态下，我们发现拓扑表面状态在SC/TI界面处经历了相当大的超导间隙开放，这在Fermi Energy的波动上也是强大的。我们还表明，微不足道的界面状态仅略有邻近，可能会妨碍该材料平台中基于majora的Qubit的实现。
Interfacing a topological insulator (TI) with an $s$-wave superconductor (SC) is a promising material platform that offers the possibility to realize a topological superconductor through which Majorana-based topologically protected qubits can be engineered. In our computational study of the prototypical SC/TI interface between Nb and Bi$_2$Te$_3$, we identify the benefits and possible bottlenecks of this potential Majorana material platform. Bringing Nb in contact with the TI film induces charge doping from the SC to the TI, which shifts the Fermi level into the TI conduction band. For thick TI films, this results in band bending leading to the population of trivial TI quantum-well states at the interface. In the superconducting state, we uncover that the topological surface state experiences a sizable superconducting gap-opening at the SC/TI interface, which is furthermore robust against fluctuations of the Fermi energy. We also show that the trivial interface state is only marginally proximitized, potentially obstructing the realization of Majorana-based qubits in this material platform.
