Superconducting Tunneling Spectroscopy of a Carbon Nanotube Quantum Dot

ORAL

Abstract

We report results on tunneling spectroscopy of a carbon nanotube quantum dot. Using a three-probe technique that includes a superconducting tunnel probe, we map out changes in conductance due to band structure, excited states, and applied bias. We also see features due to the unique nature of the superconducting probe, including enhancement of weak tunneling processes. In addition, we see~conduction inside the superconducting gap when an end to end bias is applied, which suggests some inelastic, possibly assisted, tunneling process inside the quantum dot.

*This work is support by the NSF under grant DMR-0644674 and DMR-0705213.

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Authors

  • Travis Dirks

    • Department of Physics and Materials Research Laboratory, University of Illinois
    • University of Illinois at Urbana-Champaign

  • Yung-Fu Chen

    • Department of Physics and Materials Research Laboratory, University of Illinois

  • Nadya Mason

    • Department of Physics and Materials Research Laboratory, University of Illinois at Urbana-Champaign
    • Department of Physics and Materials Research Laboratory, University of Illinois
    • University of Illinois at Urbana-Champaign

  • Norman Birge

    • Michigan State University
    • Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824
    • Dept. of Physics and Astronomy, Michigan State University, East Lansing, Mi 48824
    • Department of Physics and Astronomy, Michigan State University