1. Department of Physics and Astronomy; Hunter College of the City University of New York; 695 Park Avenue, New York, NY 10065 USA
2. Center of Integrated Nanotechnology; CINT, Los Alamos; NM 87545 USA
3. Air Force Research Laboratory; Space Vehicles Directorate, Kirtland Air Force Base; NM 87117 USA
4. Department of Physics and Engineering Physics; Fordham University; 441 East Fordham Road, Bronx, NY 10458 USA