[1] Univ Illinois, Dept Mat Sci & Engn, Urbana, IL 61801 USA
[2] Univ Illinois, Dept Mech Sci & Engn, Urbana, IL 61801 USA
[3] Korea Univ, Dept Phys, Seoul 02841, South Korea
[4] Jeju Natl Univ, Dept Phys, Jeju 63243, South Korea
[5] Korea Univ, KU KIST Grad Sch Converging Sci & Technol, Seoul 02841, South Korea
[6] Inst for Basic Sci Korea, Ctr Mol Spect & Dynam, Seoul 02841, South Korea
[7] Univ Calif Irvine, Dept Mech & Aerosp Engn, Irvine, CA 92697 USA