1. Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
2. University of Georgia, Athens, Georgia 30602, USA
3. Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
4. Department of Physics and Materials Science, University of Memphis, Memphis, Tennessee 38152, USA
5. Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA
6. Quantum Science Center, Oak Ridge, Tennessee 37831, USA
7. Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA