Multiscale Modeling : From Atoms to Devices

Observed at the macro- or microscopic scale, many properties of materials and devices are being produced or controlled by processes at the nanoscopic scale. Therefore, multiscale modeling is necessary for the design of novel materials and devices. In this book, active international researchers describe approaches, applications, design, and results of different techniques across scales. The text emphasizes models that explicitly include the atomic scale, rather than including this scale via empirical parameters. Predictive and design capabilities of models are also explored, and the book includes applications involving electron and mass transport.

While the relevant features and properties of nanosystems necessarily depend on nanoscopic details, their performance resides in the macroscopic world. To rationally develop and accurately predict performance of these systems we must tackle problems where multiple length and time scales are coupled. Rather than forcing a single modeling approach to predict an event it was not designed for, a new paradigm must be employed: multiscale modeling.

A brilliant solution to a pervasive problem, Multiscale Modeling: From Atoms to Devices offers a number of approaches for which more than one scale is explicitly considered. It provides several alternatives, from coarse-graining sampling of the atomic and mesoscale to Monte Carlo- and thermodynamic-based models that allow sampling of increasingly large scales up to multiscale models able to describe entire devices.

Beginning with common techniques for coarse-graining, the book discusses their theoretical background, advantages, and limitations. It examines the application-dependent parameterization characteristics of coarse-graining along with the "finer-trains-coarser" multiscale approach and describes three carefully selected examples in which the parameterization, although based on the same principles, depends on the actual application.

The book considers the use of ab initio and density functional theory to obtain parameters needed for larger scale models, the alternative use of density functional theory parameters in a Monte Carlo method, and the use of ab initio and density functional theory as the atomistic technique underlying the calculation of thermodynamics properties of alloy phase stability.

Highlighting one of the most challenging tasks for multiscale modelers, Multiscale Modeling: From Atoms to Devices also presents modeling for nanocomposite materials using the embedded fiber finite element method (EFFEM). It emphasizes an ensemble Monte Carlo method to high field-charge transport problems and demonstrates the practical application of modern many-body quantum theories.