High Efficiency CVD Graphene-lead (Pb) Cooper Pair Splitter.
High Efficiency CVD Graphene-lead (Pb) Cooper Pair Splitter.
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DOI：
10.1038/srep23051
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发表时间：
2016-03-14
影响因子：
4.6
通讯作者：
Tarucha S
中科院分区：
文献类型：
--
作者：
Borzenets IV;Shimazaki Y;Jones GF;Craciun MF;Russo S;Yamamoto M;Tarucha S
量子纠缠电子的产生和操纵是量子力学中的一个重要概念，也是量子信息处理发展所必需的;但在固态系统中尚未建立。超导体-双量子点库珀对分束器是一种很有前途的器件。早期的基于纳米线的器件虽然高效，但在可扩展性和进一步的电子操纵方面受到限制。我们展示了一种优化的，高效率的，CVD生长的石墨烯基库珀对分裂器。我们的设备被设计为通过邻近效应在石墨烯中诱导超导性，导致大的超导能隙Δ = 0.5 meV，相干长度Δ = 200 nm。器件的扁平特性降低了寄生电容，增加了充电能量EC。我们的设计还简化了几何限制，并最大限度地减少输出通道分离。因此，我们测量的可见度高达86%，分束效率高达62%。这将为接近单位效率、长距离分裂和分裂后电子操纵铺平道路。
Generation and manipulation of quantum entangled electrons is an important concept in quantum mechanics, and necessary for advances in quantum information processing; but not yet established in solid state systems. A promising device is a superconductor-two quantum dots Cooper pair splitter. Early nanowire based devices, while efficient, are limited in scalability and further electron manipulation. We demonstrate an optimized, high efficiency, CVD grown graphene-based Cooper pair splitter. Our device is designed to induce superconductivity in graphene via the proximity effect, resulting in both a large superconducting gap Δ = 0.5 meV, and coherence length ξ = 200 nm. The flat nature of the device lowers parasitic capacitance, increasing charging energy EC. Our design also eases geometric restrictions and minimizes output channel separation. As a result we measure a visibility of up to 86% and a splitting efficiency of up to 62%. This will pave the way towards near unity efficiencies, long distance splitting, and post-splitting electron manipulation.