Enhanced Josephson coupling in hybrid nanojunctions
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Physical Review B, Volume 107, issue 9
AbstractWe have fabricated NbN/Au nanogaps and bridged them with an Al superconductor using Ti as an interlayer. The nanodevices show a critical current density at 300 mK as high as 3×106A/cm2, which is 30% higher than that of Al nanowires with the same lateral dimensions as the NbN-based devices. The response of the critical current as a function of the external magnetic field clearly showed a Fraunhofer-like behavior, indicating a Josephson coupling between the NbN electrodes through the Al barrier. The superconducting transport evolves into different transport regimes as a function of the temperature. These findings demonstrate the importance of using superconducting barriers in hybrid nanodevices to achieve very high Josephson current in nanodevices of great relevance in superconducting circuits requiring high integration density.
Funding Information: This work was partially supported by the Foundation BLANCEFLOR Boncompagni Ludovisi and by Progetto PON RI 2014-2020 “AIM: Attraction and International Mobility.”
Montemurro , D , Golubev , D S , Kubatkin , S , Tafuri , F , Bauch , T & Lombardi , F 2023 , ' Enhanced Josephson coupling in hybrid nanojunctions ' , Physical Review B , vol. 107 , no. 9 , 094517 , pp. 1-11 . https://doi.org/10.1103/PhysRevB.107.094517