1. C. C. Tsuei, J. R. Kirtley, M. Rupp, J. Z. Sun, A. Gupta, and M. B. Ketchen are at IBM Research Division, Thomas J. Watson Research Center, Yorktown Heights, NY 10598, USA.
2. C. A. Wang, Z. F. Ren, and J. H. Wang are at Superconducting Materials Laboratory, Natural Sciences and Mathematics Complex, State University of New York, Buffalo, NY 14260, USA.
3. M. Bhushan is at Department of Physics, State University of New York, Stony Brook, NY 11794, USA.