Ah-Young Jee1, Boyce Tsang2, Steve Granick3. 1. Department of Materials Science and Engineering, University of Illinois, Urbana, Illinois 61801, USA. 2. Department of Physics, University of Illinois, Urbana, Illinois 61801, USA. 3. 1] Department of Materials Science and Engineering, University of Illinois, Urbana, Illinois 61801, USA [2] Department of Physics, University of Illinois, Urbana, Illinois 61801, USA.