The Simulation Concept – How to Exploit Tools for Computing Hybrids (SCHETCH) project is exploring the design modeling and simulation (M&S) process for developing advanced computing technology for future intelligent systems. The goal is to integrate new alternative computing concepts with existing silicon-based computing technology in hybrid computing architectures. A main premise behind this project is that, for an alternative-computing concept to move from the laboratory to a technology ready for the field, the proper M&S process must be in place. Adaptation and integration of commercially available software provides an opportunity to take advantage of existing functionality without investing time into developing new tools for new concepts. It was decided to focus on hardware concepts rather than software implementations, initially looking at three concepts: nanomechanical quantum computing, membrane computing, and deoxyribonucleic acid (DNA) computing.

(Left) The geometry mesh case for the Ion Trap Zone and (right) the resonance frequency results of the analysis. The significance of this correlation of results is that it provides an option to performing several small, simplified studies with individual models when a single model can be reused several times. The electrical characteristics were also pertinent to performance output goals of the modeling and simulation process. A stable trapping potential must be maintained to confine ions.
Quantum computation is a paradigm of information processing that may provide significant advantages over classical computing methods, allowing one to solve profound problems that are otherwise unattainable, such as the ability to factor large numbers. The physical implementation of quantum computing architectures will require novel technology and methods that are not easily supported by current design tools.

One approach to the practical development of a quantum computer involves the use of nanomechanical resonators. Nanometer-scale resonating beams are being explored as a possible avenue to exhibit quantum behaviors such as superposition and decoherence. Numerous research efforts are being conducted to simulate the behavior of these nanomechanical devices in order to understand how they can be designed, modeled, and applied to quantum computing. This potential development of quantum computers utilizing nanomechanical-based processors relies on achieving an accurate model of the mechanical system.

It was discovered that little research has been conducted on nanomaterials under both room-temperature and cryogenic conditions. A better understanding of material properties on the nanoscale and their impact on quantum mechanical modeling will be needed for future research in order to more accurately model nanodevices and systems.

A second approach to quantum computing being pursued is the use of ion traps, which encode and process data with a string of ions that are confined in a field. The field depends on the type of ion trap. The Penning Trap makes use of magnetic fields, and the Paul Trap, or Linear Trap, utilizes radio frequency (RF) electric fields. Lasers are used for inputs, as well as a means of laser-cooling ions. The promise of the ion trap lies in its basis in relatively well-known technology. Fabrication of the proper device geometry for ion trap concepts can leverage a combination of MEMS, CMOS, and Gallium Arsenide (GaAs) technology.

The structure consists of, essentially, five layers: a silicon base, two silicon dioxide surrounding layers, and two gold electrode layers. Reducing the structure into components of each layer in an assembly allowed for different material assignment with correct geometric relationships. Embedded properties and appearance for the prescribed materials allowed accuracy in representation and visualization.

Also known as P-Systems, Membrane Computing is a bio-inspired branch of natural computing, abstracting computing models from the structure and functioning of living cells and from the organization of cells in tissues or other high-order structures. It was quickly determined that the available systems biology tools were not appropriate for modeling P-Systems.

One area in biotechnology that has some potential and will need to be watched is the area of DNA self-assembly. Simply stated, this is the use of synthetic DNA to fabricate nanoelectronics. Interest in this area comes from the debate of Moore’s Law, and whether or not existing lithographic processes, currently used in electronics fabrication lines, can be refined to be applicable for the small size scales of future electronic technologies.

While several alternative computing concepts were examined under this project, a majority of the hands-on experience to date was focused on examining quantum computing concepts. It was found that commercially available three-dimensional M&S software tools can be used to analyze concepts for physical components of quantum computing concepts. The biggest gap was the lack of a clear understanding and proper definition of material properties for modeling structures at the nanoscale.

This work was done by Clare D. Thiem and Joseph M. Hertline of the Air Force Research Laboratory. For more information, download the Technical Support Package (free white paper) at  under the Electronics/Computers category. AFRL-0137

This Brief includes a Technical Support Package (TSP).
Simulation Concept Exploits Tools for Computing Hybrids

(reference AFRL-0137) is currently available for download from the TSP library.

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