High Efficiency CVD Graphene-lead (Pb) Cooper Pair Splitter
Borzenets, IV; Shimazaki, Y; Jones, GF; et al.Craciun, Monica F.; Russo, Saverio; Yamamoto, Y; Tarucha, Seigo
Date: 14 March 2016
Publisher DOI
Abstract
We demonstrate high efficiency Cooper pair splitting in a graphene-based device. We utilize a true Y-shape design effectively placing the splitting channels closer together: graphene is used as the central superconducting electrode as well as QD output channels, unlike previous designs where a conventional superconductor was used with ...
We demonstrate high efficiency Cooper pair splitting in a graphene-based device. We utilize a true Y-shape design effectively placing the splitting channels closer together: graphene is used as the central superconducting electrode as well as QD output channels, unlike previous designs where a conventional superconductor was used with tunnel barriers to the quantum dots (QD) of a different material. Superconductivity in graphene is induced via the proximity effect, thus resulting in both a large measured superconducting gap $\Delta=0.5$meV, and a long coherence length $\xi=200$nm. The graphene-graphene, flat, two dimensional, superconductor-QD interface lowers the capacitance of the quantum dots, thus increasing the charging energy $E_C$ (in contrast to previous devices). As a result we measure a visibility of up to 96% and a splitting efficiency of up to 62%. Finally, the devices utilize graphene grown by chemical vapor deposition allowing for a standardized device design with potential for increased complexity.
Engineering
Faculty of Environment, Science and Economy
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