Metallofullerenes in Composite Carbon Nanotubes as a Nanocomputing Memory Device

Here, we investigate a hybrid carbon nanostructure, which comprises two single-open host nanotubes of the same radius and joined by another single-open nanotube, which is centrally located between the host nanotubes but has a smaller radius. A metallofullerene is then enclosed inside the structure to represent a bit information and is originally located inside one of the host nanotubes. The geometric parameters, such as the radii of nanotubes and fullerene radius are purposely chosen so that the metallofullerene cannot enter the central nanotube without additional energy. By applying an external electrical field, the metallofullerene can overcome the energy barrier and pass from one end to the other end to form a two-state fullerene shuttle memory device. The key geometric parameters are provided for a range of fullerenes, including C₆₀, C ₈₀, and C₁₀₀, noting that we assume most metallofullerenes take the form M@C₆₀, M@C₈₀, and M@C₁₀₀, where M denotes a metal atom or ion located noncovalently inside the fullerene C_n.