Between July 18 and 20, 2012, Professor Moses Chan, a member of the American Academy of Sciences and the inaugural director of Center for the Nanoscale Science in Pennsylvania State University, paid a visit to the China High Magnetic Field Laboratory (CHMFL) in Hefei, the Chinese Academy of Sciences. During his visit, he presented a lecture entitled “Superconductivity in Nanowires: Macroscopic Quantum Tunneling”.
In his talk, he presented evidence of individual quantum phase slips (QPS), quantum mechanical tunneling events that gives rise to momentarily electrical resistance in superconducting aluminum nanowires. QPS appear as stochastic switching from deep in the superconducting state to the normal resistive state upon the injection of a discrete current pulse. QPS are seen only in the low temperature limit when the electrodes contacting the wires are superconducting. When the electrodes are normal at a higher temperature, QPS are suppressed. This is the case because the normal electrodes provide a dissipative environment, i.e., the Calderia-Leggett model of quantum tunneling, that stabilize the superconducting state of the nanowires.
His speech was very interesting and vivid, attracted our attendance a lot. Furthermore, he was also extremely expressed by the great progress of the construction of our CHMFL and the achievement in research.
Professor Chan received his Ph.D from Cornell University in 1974. He became the Evan Pugh Professor, the highest honor in Penn State University, since 1994. He became a fellow of the American Physical Society in 1987, a member of the American Academy of Science in 2000, and a fellow of American Association for the Advancement of Sciences in 2007. He was the recipient of the 16th Fritz London Memorial Prize in 1996. He has served as an associate editor of Physical Review Letters for many years and one of the Overseas science and technology advisory and consultative experts appointed by the Hong Kong SAR Government. Professor Chan had made outstanding contributions to the fundamental research in condensed matter physics. His numerous achievements appear in major publications such as Nature, Science, Nature Physics, and Physical Review Letters.