Direct observation of gate-controlled Josephson inductance in multiwalled carbon nanotube

ORAL

Abstract

Electrometers based on Cooper pair tunneling are, in principle, dissipationless, and thus advantageous due to their small back action noise. We have studied the so called L-SET circuit, in which the frequency of Josephson plasma oscillations in a superconducting junction device is tuned below one GHz by a parallel $LC$ circuit. In the present work, we have used a Josephson junction made out of a multiwalled carbon nanotube with Pd/Nb contacts. We observe gate-tunable critical currents up to $I_c \sim 10$ nA, which are deduced from shifts in the LC-circuit resonance frequency caused by the Josephson inductance ($\propto I_c^{-1}$) of the MWNT junction. This work was financially supported by Academy of Finland and by European Union (CARDEQ, FP6-IST-021285-2).

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Authors

  • Antti Paila

    • Low Temperature Laboratory, Helsinki University of Technology

  • Lorenz Lechner

    • Low Temperature Laboratory, Helsinki University of Technology

  • Markus Gaass

    • Institute for Experimental and Applied Physics, University of Regensburg

  • Christoph Strunk

    • Institute for Experimental and Applied Physics, University of Regensburg

  • Mika Sillanp\"a\"a

    • Low Temperature Laboratory, Helsinki University of Technology

  • Pertti Hakonen

    • Low Temperature Laboratory, Helsinki University of Technology