We measure the conductance of carbon nanotube peapods from room temperature down to $250\mathrm{mK}$. Our devices show both metallic and semiconducting behavior at room temperature. At the lowest temperatures, we observe single electron effects. Our results suggest that the encapsulated ${\mathrm{C}}_{60}$ molecules do not introduce substantial backscattering for electrons near the Fermi level. This is remarkable, given that previous tunneling spectroscopy measurements show that encapsulated ${\mathrm{C}}_{60}$ strongly modifies the electronic structure of a nanotube away from the Fermi level.

• Received 27 March 2007

DOI:https://doi.org/10.1103/PhysRevB.76.073404