LaGasse Samuel W, Cress Cory D
NRC Postdoc Residing at the Electronics Science and Technology Division, United States Naval Research Laboratory, Washington D.C. D.C. 20375, United States.
Electronics Science and Technology Division, United States Naval Research Laboratory, Washington D.C. 20375, United States.
Nano Lett. 2020 Sep 9;20(9):6623-6629. doi: 10.1021/acs.nanolett.0c02443. Epub 2020 Aug 4.
We propose a technique based on nonlocal resistance measurements for mapping transport in electron optics experiments. Utilizing tight-binding transport methods, we show how to use a four-terminal measurement to isolate the ballistic transport from a single lead of interest and reconstruct its contribution to the local density of states. This enables us to propose an experimentally tractable four-terminal device with via contacts for measuring Veselago lensing in a graphene - junction. Furthermore, we demonstrate how to extend this method as a scanning probe technique, implementing mapping of complex electron optics experiments including angled junctions, collimation optics, and beam steering. Our results highlight the fundamental importance of electron dephasing in ballistic transport and provide guidelines for isolating electron optics signals of interest. These findings unveil a fresh approach to performing electron optics experiments, with a plethora of two-dimensional material platforms to explore.
我们提出了一种基于非局部电阻测量的技术，用于绘制电子光学实验中的输运情况。利用紧束缚输运方法，我们展示了如何使用四端测量来从感兴趣的单个引线中分离出弹道输运，并重建其对局部态密度的贡献。这使我们能够提出一种实验上易于处理的带有通孔接触的四端器件，用于测量石墨烯结中的韦谢拉戈透镜效应。此外，我们演示了如何将该方法扩展为一种扫描探针技术，实现对包括角结、准直光学和光束转向在内的复杂电子光学实验的映射。我们的结果突出了电子退相干在弹道输运中的根本重要性，并为分离感兴趣的电子光学信号提供了指导。这些发现揭示了一种进行电子光学实验的新方法，有大量二维材料平台可供探索。
