1. Micron School for Materials Science and Engineering, Boise State University, Boise, Idaho 83725, United States
2. Department of Electrical & Computer Engineering, Boise State University, Boise, Idaho 83725, United States
3. Department of Physical Science, Southern Utah University, Cedar City, Utah 84720, United States
4. Department of Physics, California State University, Chico, Chico, California 95929, United States