Surface electron perturbations and the collective behaviour of atoms adsorbed on a cylinder

Abstract

Charge transfer from adsorption is shown to provide an electrical method for probing the collective behaviour of atoms and small molecules confined to the surface of a carbon nanotube. A single-walled carbon nanotube presents a seamless cylindrical graphene surface and is thus an ideal adsorption substrate for investigating the physics of atoms and molecules in two dimensions and approaching the one-dimensional limit1,2,3,4,5,6,7. When a suspended nanotube is made into a transistor, frequency shifts of its mechanical resonances allow precise measurement of the adsorbed mass down to the single-atom level8,9,10. Here we show that its electrical characteristics are also modified by the adsorbed atoms and molecules, partly as a result of a small charge transfer between them and the carbon surface. We quantify this charge transfer, finding it similar for many different species, and use the associated sensitivity of the conductance to carry out the studies of phase transitions, critical scaling, dynamical fluctuations and dissipative metastable states in a system of interacting atoms confined to a cylindrical geometry.