Design of a two-state shuttle memory device

Abstract

In this study, we investigate the mechanics of a metallofullerene shuttle memory device, comprising a metallofullerene which is located inside a closed carbon nanotube. The interaction energy for the system is obtained from the 6-12 Lennard-Jones potential using the continuum approximation, which assumes that a discrete atomic structure can be replaced by an average atomic surface density. This approach shows that the system has two equal minimum energy positions, which are symmetrically located close to the tube extremities, and therefore it gives rise to the possibility of being used as a two-state memory device. On one side the encapsulated metallofullerene represents the zero information state and by applying an external electrical field, the metallofullerene can overcome the energy barrier of the nanotube, and pass from one end of the tube to the other end, where the metallofullerene then represents the one information state. By appropriately selecting different nanotube geometries, the memory device can be designed to have various data transfer rates. In particular, design parameters are presented for the optimization of the data transfer rates and the stabilization of the data storage. The former involves optimization of the nanotube length and the applied electric field, while the latter involves the nanotube radius and the choice of metallofullerene.