1. Department of Applied Engineering and Physics, Cornell University, Ithaca, New York 14850, USA
2. Department of Physics, Cornell University, Ithaca, New York 14850, USA
3. Department of Rheology, Anton Paar, Ashland, Virginia 23005, USA
4. Department of Physics, Brandeis University, Waltham, Massachusetts 02453, USA
5. Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, New York, USA