title: Local gate control of a carbon nanotube double quantum dot.
abstract: We have measured carbon nanotube quantum dots with multiple electrostatic gates and used the resulting enhanced control to investigate a nanotube double quantum dot. Transport measurements reveal honeycomb charge stability diagrams as a function of two nearly independent gate voltages. The device can be tuned from weak to strong interdot tunnel-coupling regimes, and the transparency of the leads can be controlled independently. We extract values of energy-level spacings, capacitances, and interaction energies for this system. This ability to control electron interactions in the quantum regime in a molecular conductor is important for applications such as quantum computation.
authors.affiliation: Department of Physics, Harvard University Cambridge, MA 02138, USA. nmason@fas.harvard.edu
authors.forename: N
authors.initials: N
authors.lastname: Mason
authors.forename: M J
authors.initials: MJ
authors.lastname: Biercuk
authors.forename: C M
authors.initials: CM
authors.lastname: Marcus