1. Division of Materials Science and Engineering, Boston University, Boston, Massachusetts 02215, United States
2. Department of Mechanical and Materials Science Engineering, Cyprus University of Technology, P.O. Box 50329, 3603 Limassol, Cyprus
3. Department of Electrical and Computer Engineering, Boston University, Boston, Massachusetts 02215, United States
4. Oden Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, Texas 78712, United States
5. Department of Physics, The University of Texas at Austin, Austin, Texas78712, United States