发表机构
Budapest University of Technology and Economics; National Institute for Materials Science（布达佩斯技术与经济大学; 国立材料研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出基于门反射测量的电容传感方法，用于双层石墨烯异质结构，可跟踪带隙开启、识别层间对齐，并支持双谐振器读出以提取层极化率，为拓扑相研究提供可扩展方案。
AI 中文摘要
在寻找双层石墨烯拓扑态的过程中，电容测量方法广泛应用于电桥型读出或源漏反射测量装置中。本文展示了一种基于门反射测量的替代读出方法。我们通过一个集总元件LC谐振器耦合到异质结构的顶栅电极，探测封装在hBN和WSe$_2$之间的BLG薄片的电容。微波读出可靠地跟踪了器件中位移场诱导带隙的开启。与同时进行的直流输运测量相比，射频信号受样品无序引起的渗流输运通道的影响较小。此外，我们利用基于门的读出识别了hBN和BLG薄片之间的小角度对齐。从固定频率的微波读出中，我们提取了双层在绝缘态和金属态之间的器件电容变化，并利用一个全面的电容网络模型来解释其起源。最后，我们提出了一种先进的、多路复用的双谐振器读出方案，能够同时测量顶栅和底栅电容，以提取系统的层极化率。这项工作确立了门反射测量作为一种高度可扩展且强大的方法，用于探索范德华异质结构中的拓扑相和内部电荷动力学。
英文摘要
In the search for topological states in bilayer graphene, capacitance measurement methods are widely utilized in bridge type readouts or source-drain reflectometry setups. In this paper we demonstrate an alternative readout method based on gate reflectometry. We probe the capacitance of a BLG flake encapsulated between hBN and WSe$_2$ through a lumped-element LC resonator coupled to the top gate electrode of the heterostructure. The microwave readout reliably tracks the opening of a displacement field-induced band gap in the device. Compared to simultaneous DC transport measurements, the RF signal proves to be less affected by the percolating transport channels caused by sample disorder. Furthermore, we use the gate based readout to identify a small-angle alignment between the hBN and BLG flake. From the fixed frequency microwave readout, we extract the device capacitance change between the insulating and metallic state of the bilayer and utilize a comprehensive capacitance network model to explain its origin. Finally, we propose an advanced, multiplexed double-resonator readout scheme capable of simultaneously measuring top and bottom gate capacitances to extract the layer polarizability of the system. This work establishes gate reflectometry as a highly scalable and powerful methodology for exploring topological phases and internal charge dynamics in van der Waals heterostructures.
CommentsThe following article has been submitted to the Journal of Applied Physics. 21 pages, 16 figures
