1. Department of Electrical and Computer Engineering University of Massachusetts Amherst MA 01003 USA
2. Hewlett Packard Labs Palo Alto CA 94304 USA
3. Department of Physics Loughborough University Loughborough LE11 3TU UK
4. Air Force Research Lab Information Directorate Rome NY 13441 USA
5. Center for Functional Nanomaterials Brookhaven National Laboratory Upton NY 11973 USA