Evolution of transport regimes in carbon nanotube quantum dots.

Journal Article (Journal Article)

We study the evolution of conductance regimes in carbon nanotubes with doubly degenerate orbitals (shells) by controlling the contact transparency within the same sample. For sufficiently open contacts, Kondo behavior is observed for 1, 2, and 3 electrons in the topmost shell. As the contacts are opened more, the sample enters the "mixed valence" regime, where different charge states are strongly hybridized by electron tunneling. Here, the conductance as a function of gate voltage shows pronounced modulations with a period of four electrons, and all single-electron features are washed away at low temperature. We successfully describe this behavior by a simple formula with no fitting parameters. Finally, we find a surprisingly small energy scale that controls the temperature evolution of conductance and the tunneling density of states in the mixed valence regime.

Full Text

Duke Authors

Cited Authors

  • Makarovski, A; Liu, J; Finkelstein, G

Published Date

  • August 2007

Published In

Volume / Issue

  • 99 / 6

Start / End Page

  • 066801 -

PubMed ID

  • 17930850

Electronic International Standard Serial Number (EISSN)

  • 1079-7114

International Standard Serial Number (ISSN)

  • 0031-9007

Digital Object Identifier (DOI)

  • 10.1103/physrevlett.99.066801


  • eng