On July 21, Science published Observation of the Efimovian Expansion in Scale-Invariant Fermi Gases, a paper covering the research achievement jointly made by Prof. Wu Haibin’s team of ECNU’s State Key Laboratory of Precision Spectroscopy, Prof. Zhai Hui’s team of Tsinghua University, and Associate Prof. Qi Ran’s team of Renmin University.
Science 22 Jul 2016:Vol. 353, Issue 6297
Cold atomic gases are often studied while confined in parabolic traps, with the largest atomic density at the center of the trap. When the trap is made shallower, the gas radially expands as the energy cost for atoms that are farther from the trap center decreases. Prof. Wu and his colleagues observed an interesting effect when they reduced the characteristic frequency of the parabolic trap so that it was at any moment inversely proportional to the elapsed time. Instead of expanding continuously, a strongly interacting Fermi gas held in such a trap stalled at certain time points. These time points formed a geometric progression, a consequence of scale invariance in the strongly interacting limit. Their finding has important application prospects in the future of cold atomic research and will open up many new research perspectives.
Prof. Wu and his team members.
Wu received his Ph.D in Physics from the University of Arkansas in 2009. After that, he worked as a postdoctoral fellow at Duke University for two years and became a professor in ECNU’s State Key Laboratory of Precision Spectroscopy in 2012.
Prof. Wu
Wu focuses his research in quantum optics and the strong interaction of ultracold atomic gases.
