Varnava Nicodemos, Wilson Justin H, Pixley J H, Vanderbilt David
Department of Physics & Astronomy, Center for Materials Theory, Rutgers University, Piscataway, NJ, USA.
Center for Computational Quantum Physics, Flatiron Institute, New York, NY, USA.
Nat Commun. 2021 Jun 28;12(1):3998. doi: 10.1038/s41467-021-24276-5.
Engineering and manipulation of unidirectional channels has been achieved in quantum Hall systems, leading to the construction of electron interferometers and proposals for low-power electronics and quantum information science applications. However, to fully control the mixing and interference of edge-state wave functions, one needs stable and tunable junctions. Encouraged by recent material candidates, here we propose to achieve this using an antiferromagnetic topological insulator that supports two distinct types of gapless unidirectional channels, one from antiferromagnetic domain walls and the other from single-height steps. Their distinct geometric nature allows them to intersect robustly to form quantum point junctions, which then enables their control by magnetic and electrostatic local probes. We show how the existence of stable and tunable junctions, the intrinsic magnetism and the potential for higher-temperature performance make antiferromagnetic topological insulators a promising platform for electron quantum optics and microelectronic applications.
在量子霍尔系统中已经实现了对单向通道的工程设计和操控，这促成了电子干涉仪的构建以及针对低功耗电子学和量子信息科学应用的相关提议。然而，要完全控制边缘态波函数的混合与干涉，就需要稳定且可调谐的结。受近期候选材料的鼓舞，在此我们提议利用一种反铁磁拓扑绝缘体来实现这一点，该绝缘体支持两种不同类型的无隙单向通道，一种来自反铁磁畴壁，另一种来自单高度台阶。它们独特的几何性质使其能够稳固相交形成量子点结，进而能够通过磁性和静电局部探针进行控制。我们展示了稳定且可调谐的结的存在、固有磁性以及更高温度性能的潜力如何使反铁磁拓扑绝缘体成为电子量子光学和微电子应用的一个有前景的平台。
