Carbon nanotube quantum resistors
The conductance of multiwalled carbon nanotubes (MWNTs) was found to be quantized. The experimental method involved measuring the conductance of nanotubes by replacing the tip of a scanning probe microscope with a nanotube fiber, which could be lowered into a liquid metal to establish a gentle electrical contact with a nanotube at the tip of the fiber. The conductance of arc-produced MWNTs is one unit of the conductance quantum G0 = 2e2/h = (12.9 kilohms)-1. The nanotubes conduct current ballistically and do not dissipate heat. The nanotubes, which are typically 15 nanometers wide and 4 micrometers long, are several orders of magnitude greater in size and stability than other typical room-temperature quantum conductors. Extremely high stable current densities, J > 10(7) amperes per square centimeter, have been attained.
Frank
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S. Frank, P. Poncharal, W. A. de Heer, School of Physics, Georgia Institute of Technology, Atlanta GA 30332, USA. Z. L. Wang, School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta GA 30332, USA.
Poncharal
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Wang
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Heer
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