****Technical Abstract**** This project will pursue experiments to investigate fundamental aspects of the behavior of matter in low dimensions, such as the dynamics of phase transitions in one or two dimensions. It will also investigate methodically the interactions between atoms adsorbed on a carbon surface and electrons in that surface, which is of wide-reaching relevance to uses of graphitic carbon in sensing, filtration, and storage of gases and of electrical charge. The technique used is to adsorb atomic and molecular layers on individual single-walled carbon nanotubes suspended like miniature guitar strings. The change in vibrational frequency due to mass loading yields the density of atoms to near atomic precision while the effect on the current along the nanotube simultaneously reveals the effect of the atoms on the electrons with better than single-electron precision. The approach will in due course be extended to lower temperatures where exotic quantum fluid and solid behavior may occur confined to the cylindrical geometry of the nanotube surface, and also to graphene and other substrates. The project will support the education of two PhD students and several undergraduates in the wide range of techniques and principles of nanoscale physics and nanotechnology.
Carbon materials play crucial roles in many technologies, such as filtering, gas storage, and lithium ion batteries, which rely on the interactions of the surface of the carbon with atoms and molecules. Those interactions are complex and surprisingly poorly understood. This project will pursue experiments on the nanoscale that will allow far more precise and methodical determination and understanding of the interactions than has been possible before. The technique involves exposing carbon-nanotube "nanoguitar transistors" and later graphene "nanodrums" to gases at carefully controlled temperature and pressure. By measuring the change in pitch of the nanoguitar or drum, the number of atoms stuck to the surface can be accurately measured, while at the same time by measuring changes in the electrical resistance the interaction with the electrons can be determined with extraordinary precision. On the other hand, the same techniques will be employed at very low temperatures to investigate the fundamental physics of superfluidity and quantum confinement of matter restricted to the surface of a long thin cylinder. The project will be carried out by two PhD students and several undergraduates who will be familiarized with the wide range of techniques and principles of nanoscale physics and nanotechnology.
