发表机构
RWTH Aachen University; Forschungszentrum Jülich; National Institute for Materials Science（亚琛工业大学; 于利希研究中心; 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
本研究利用栅极定义的量子点作为局部光谱探针，在双层石墨烯与超导NbSe2近邻化的全二维平台上探测到高达80微电子伏特的近邻诱导超导能隙，并发现其可延伸超过1微米，展示了可控的超导-量子点混合平台。
AI 中文摘要
范德华异质结构提供了一种直接的方式，将具有不同电子性质的二维（2D）材料（如2D半导体、金属和超导体）组合在单个器件中。在此背景下，双层石墨烯（BLG）特别有吸引力，因为其电可调的带隙能够实现对隧穿势垒和量子点的局部控制。在这里，我们实现了一个基于BLG与超导NbSe$_2$近邻化的全二维混合平台。利用局部静电栅极，我们在横向超导体-半导体界面的不同距离处定义了隧穿势垒和量子点。量子点作为近邻化BLG沟道段的局部光谱探针，形成了可调的超导体-量子点-正常导体结器件。库仑阻塞和有限偏压光谱揭示了一个高达$80\\,\mathrm{μeV}$的近邻诱导超导能隙，并允许追踪其随距NbSe$_2$接触距离增加而演化的过程。我们发现，局部态密度在超过1 $μ$m的距离上仍然受到抑制，这与通过高弹道BLG沟道的超导近邻效应一致。我们的结果表明，BLG-超导体混合体提供了一个可控平台，在该平台上量子点和量子点接触可以与超导电性很好地结合。
英文摘要
Van der Waals heterostructures offer a direct way of combining two-dimensional (2D) materials with different electronic properties, such as 2D semiconductors, metals, and superconductors, in a single device. Bilayer graphene (BLG) is particularly attractive in this context, as its electrically tunable band gap enables local control of tunnel barriers and quantum dots. Here, we realize an all-2D hybrid platform based on BLG proximitized by superconducting NbSe$_2$. Using local electrostatic gates, we define tunnel barriers and quantum dots at different distances from the lateral superconductor-semiconductor interface. The quantum dots serve as local spectroscopic probes of the proximitized BLG channel segment, forming tunable superconductor-quantum dot-normal conductor junction devices. Coulomb blockade and finite-bias spectroscopy reveal a proximity-induced superconducting gap of up to $80\,\mathrm{μeV}$ and allow to track its evolution with increasing distance from the NbSe$_2$ contact. We find that the local density of states remains suppressed over distances exceeding 1 $μ$m, consistent with superconducting proximity through a highly ballistic BLG channel. Our results show that BLG-superconductor hybrids offer a controllable platform where quantum dots and quantum point contacts can be well combined with superconductivity.
