超伝導－グラフェン接合を利用した量子エンタングラー

使用超导石墨烯结的量子纠缠器

• 批准号: 13F03019
• 负责人: 樽茶 清悟
• 金额: $ 1.54万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for JSPS Fellows
• 财政年份: 2013
• 资助国家: 日本
• 起止时间: 2013-04-01 至 2015-03-31
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13F03019/
• 关键词: graphene; quantum entangler; quantum computing; superconductivity; nanotechnology; solid state; low temperature physics; グラフェン; ジョセフソン接合; 量子もつれ

I have successfully demonstrated high efficiency Cooper pair splitting in a graphene-based device. A source of entangled electrons is essential to the future of Quantum computing. Cooper pair splitter device is one of the most successful solid state sources of entangled electrons so far, with efficiencies above 90%. Our device is modeled on the superconductor-two quantum dot device; however, we utilize a true “Y-shape” design effectively placing the splitting channels closer together. Moreover, unlike previous designs where a conventional superconductor was used with tunnel barriers to the quantum dots (QD) of a different material, we utilize graphene as the central superconducting electrode as well as QD output channels. Superconductivity in graphene is induced via the proximity effect, thus resulting in both a large measured superconducting gap Δ, and a long coherence length. The graphene-graphene, flat, two dimensional, superconductor-QD interface lowers the capacitance of the quantum dots, thus increasing the charging energy. As a result we measured a splitting efficiency of up to 62%. Finally, the devices utilize CVD grown graphene allowing for a standardized device design with potential for increased complexity and industrialization.

我已经成功地证明了在基于石墨烯的设备中的高效库珀对分裂。纠缠电子的来源对量子计算的未来至关重要。库珀对分裂器是迄今为止最成功的固态纠缠电子源之一，其效率超过90%。我们的设备是在超导体-两个量子点设备上建模的;然而，我们利用真正的“Y形”设计，有效地将分裂通道更紧密地放置在一起。此外，与以前的设计不同，传统的超导体与不同材料的量子点（QD）的隧道势垒一起使用，我们利用石墨烯作为中心超导电极以及QD输出通道。石墨烯中的超导性是通过邻近效应诱导的，因此导致大的测量超导间隙Δ和长的相干长度。石墨烯-石墨烯、平坦的二维超导体-QD界面降低了量子点的电容，从而增加了充电能量。结果，我们测量到高达62%的分裂效率。最后，这些器件利用CVD生长的石墨烯，允许标准化的器件设计，具有增加复杂性和工业化的潜力。

项目成果

Graphene/Lead (Pb)-based Cooper -pair splitter

石墨烯/铅 (Pb) 基库珀对分光器

• 发表时间: 2015
• 作者: Kayo D;Kanda S;Zempo B;Oka Y;Ivan Borzenets，Yuya Shimazaki，Gareth Jones，Monica Craciun，Saverio Russo，Michihisa Yamamoto，Seigo Tarucha
• 通讯作者: Ivan Borzenets，Yuya Shimazaki，Gareth Jones，Monica Craciun，Saverio Russo，Michihisa Yamamoto，Seigo Tarucha