1. Materials Science and Engineering, University of Utah, 50 S. Central Campus Drive, Salt Lake City, Utah 84122, USA
2. Department of Physics and Astronomy, University of Toledo, Toledo, Ohio 43606, USA
3. Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA
4. Department of Electrical Engineering, University of South Florida, 4202 E. Fowler Ave., Tampa, Florida 33620, USA
5. Electrical and Computer Engineering, University of Utah, 50 S. Central Campus Drive, Salt Lake City, Utah 84122, USA