| 研究実績の概要 |
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.
|
