1. School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, USA
2. Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, USA
3. School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907, USA
4. Laboratory of Computational Science and Modeling, Institut des Matériaux, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
5. Technology Development, Micron Technology, Inc., Boise, Idaho 83707, USA
6. Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Hong Kong