1. K. Krishana and N. P. Ong, Joseph Henry Laboratories of Physics, Princeton University, Princeton, NJ 08544, USA.
2. Q. Li, Materials Science Division, Brookhaven National Laboratory, Post Office Box 5000, Upton, NY 11973, USA.
3. G. D. Gu, School of Physics, University of New South Wales, Sydney 2052, Australia.
4. N. Koshizuka, Superconductivity Research Laboratory, International Superconductivity Technology Center, 10-13, Shinonome 1-chrome, Koto-ku, Tokyo 135, Japan.