1. School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
2. Department of Physics, Michigan Technological University, Houghton, Michigan 49931, United States
3. Department of Mechanical Engineering and Engineering Mechanics, Michigan Technological University, Houghton, Michigan 49931, United States
4. Department of Industrial and Manufacturing Engineering, Florida State University, Tallahassee, Florida 32306, United States