Carbon Nanotube Quantum Resistors

TLDR

Carbon nanotubes are 15 nm wide and 4 µm long, vastly larger and more stable than other room‑temperature quantum conductors. The conductance was measured by attaching a nanotube fiber to a scanning probe tip and contacting it with liquid metal, revealing ballistic, heat‑free transport. Multiwalled carbon nanotubes exhibit quantized conductance equal to one conductance quantum and can sustain current densities exceeding 10⁷ A cm⁻².

Abstract

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.