Ross, F. M., Reports on Progress in Physics
73 (2010), p 114501.
Kallesoe, C., et al., Nano Lett
12 (2012), p 2965.
Chou, Y.-C., et al., in preparation (2015).
 We acknowledge the National Science Foundation (Grants No. DMR-0606395 and 0907483), ERC Grant 279342: InSituNANO, the National Science Council of Taiwan (Grant NSC-101-2112-M-009-021-MY3), the Center for Interdisciplinary Science (MOE-ATU project for NCTU) and the Center for Functional Nanomaterials, Brookhaven National Laboratory, which is supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under contract DE-AC02-98CH10886; C. Czarnik for assistance with image processing and A. W. Ellis for technical support..