Local gate control of a carbon nanotube double quantum dot.
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.
Mason
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Department of Physics, Harvard University Cambridge, MA 02138, USA. nmason@fas.harvard.edu
Biercuk
M J
MJ
Marcus
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CM