Lead Investigators: N. Chandra, L. Gelb
Nanotechnology is the creation and utilization of functional materials, devices and systems with novel properties and functions that are achieved through the control of matter atom by atom, molecule by molecule, or at the macromolecular level. Nanoscale is not just another step towards miniaturization, but it is qualitatively a new scale, primarily because of the quantum mechanical interactions occurring at this scale.
It leads to new properties, phenomena, processes and functionalities that materials exhibit at sizes between isolated atoms or molecules and bulk materials. In the recent years, there have been spectacular developments in nanoscale systems. Examples are molecular electronics, with the promise to increase the speeds of present day computers many times, and mechanical systems utilizing ultra high stiffness nano tubes that appear to be a distinct possibility now.
Modeling efforts in nanoscale systems predominantly use atomistic simulations based on molecular dynamics or other refined techniques such as density-functional and tight-binding theories. Molecular dynamics, as a modeling technique fills a gap between quantum mechanical treatments and continuum simulations. It explicitly includes all the atomic degrees of freedom; consequently, it imposes severe space-time limitations. For example, a 0.1 micron cube of material might require 15 million atoms to be simulated. Further, the time resolution of such simulations should be in the order of the atomic vibration frequency to ensure conservation of energy, which is in the range of femto-pico seconds.
The majority of the simulations in the current literature are performed for systems with only 500 to 50000 atoms, jet simulations of up to 500 million atoms have been demonstrated using massive parallel computing techniques. Multi-million atom simulations are needed for understanding vital but complex problems in computational mechanics and materials science such as crack propagation, interfaces, and grain boundary sliding in poly-crystals.
The simulation of nano-grained and nanometer sized electronic systems holds particularly interesting prospects. In such problems, further advances in computational capacity could enable the models to reach the physical dimensions of the full problem. Possibly, atomic level simulations of structural nano-circuits may improve the very computer chips that make atomic level simulations possible in the first place.
Significant research funding and efforts in the area of nano technology have been recently initiated at NSF, DOD and DOE organizations. The center will not only focus on maximizing the number of atoms in atomistic simulations, but also apply multi-scale modeling methods to design nano devices, a challenging scientific and manufacturing problem.