Designing Carbon-Based Nanotechnology on a Supercomputer

David Tomanek
Michigan State University

Quantum nature of phenomena, which underlies the behavior of nanotubes and other nanostructures, raises new challenges when trying to predict their physical behavior. Addressing this challenge is imperative in view of the continuous reduction of device sizes, which is rapidly approaching the atomic scale. Due to the unavoidable influence of the measurement process on the result in the quantum regime, predictive calculations on high-performance computers have emerged as a powerful research tool complementing experimental observations.

In this presentation, I will review recent computer simulations, which shed light onto some of the puzzling behavior observed in carbon nanostructures, such as nanotubes, fullerenes, and diamondoids [1]. Due to the stability of the sp2 bond, carbon fullerenes and nanotubes are thermally and mechanically extremely stable and chemically inert. They contract rather than expand at high temperatures, and are unparalleled thermal conductors. Nanotubes may turn into ballistic electron conductors or semiconductors, and even acquire a permanent magnetic moment. In nanostructures that form during a hierarchical self-assembly process, even defects may play a different, often helpful role. sp2 bonded nanostructures may change their shape globally by a sequence of bond rotations, which turn out to be intriguing multi-step processes. At elevated temperatures or following photo-excitation, efficient self-healing processes may repair defects, thus answering an important concern of molecular electronics.

Presentation (PDF File)

Back to Workshop II: Multiscale Modeling in Condensed Matter and Materials Sciences, including Mini-Workshop: Time Acceleration Methods in Atomistic Simulations