1. Physics and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
2. School of Natural Sciences, University of California Merced, Merced, California 95344, United States
3. Department of Mechanical Science and Engineering, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana−Champaign, Champaign, Illinois 61820, United States
4. Department of Physics, Northeastern University, Boston, Massachusetts 02120, United States