2006 News

11/1/2006: Cheng Chin received Packard Fellowship


10/09/2006: HEP seminar Ed (Bucher) invited me to give a HEP seminar talk on "the enhanced sensitivity on the variation of fundamental constants in cold atoms and molecules near Feshbach resonances".


10/05/2006: Visit Toledo University Invited by Prof. Bo Gao, I went to Toledo univeristy and gave a talk on cold atom expeirments in the strongly interacting regime. It was nice to meet Bo, whose theory first predicted the bunching of s-, g- and l-wave Feshbach resonances in cesium atoms.


9/30/2006: Going-away party for Selim From 2 to 6pm, we had a party in my flat for Selim, who has stayed with us for two months. We had a major vegetarian hot pot and special dessert made by Selim. Previous night we also had a group buffet and later we went to a Jazz bar and had a great time. It is great to have Selim with us during the construction of the expeirmnet.


9/28/2006: Moving to CIS building! We moved into our new laboratories in the CIS (Center for Integrative Science) building today. The new building has passed all the tests on vibrational noise, acoustic noise, temperature and moisture controls. We really look forward to setting up our system in the new lab and can start doing expeirment!


9/03/2006~9/12/2006: The 4th COE sumposium on Physics of Self-Oranization Systems Invited by Prof. Kurihara and Prof. Terasaki, I gave a talk on degenerate Fermi gases at Waseda university. I also visited Takahashi's Yb and Rb groups in Kyoto University, Katori's precision measurements in optical lattices and Inouye's K-Li mixture experiments in Tokyo University. I gave 4 talks in Japan and had interesting discussions with Prof. Yoji Ohashi and Prof.Ueda. After Japan, I visited Prof. Tsai's group in NCKU, visited Dr. Ho in IAMS, Academic Sinica in Taiwan and gave two talks.


8/29/2006: Going-away party for Shuo Hao in 7-10.


8/27/2006: Assemble the main chamber With Jeff, Xibo and Selim, we assembled the chamber on Sunday. We are very happy everything went well and it looks really cool.


8/20/2006: Group BBQ Sunday afternoon... beautiful weather... Chen-Lung, Shuo, Selim, Dennis, other friends of theirs and I went to lakeshore (Michigan lake) and had a summer BBQ party. :)


8/10/2006: Group trip: Chicago White Sox vs. New York Yankee in the US Cellular Field Dennis, Chen-Lung, Eric, Gilbert (visitor), Bob and I went to the game. White Sox won.


8/8/2006: Prof. Johannes Hecker Denschlag from Innsbruck University visited us Johannes and his wife Nancy came to Chicago area and I am very happy to meet them and learned more about Johannes' recent exciting results. He gave a talk on "Repulsive atom pairs in an optical lattice" which is fascinating. After his talk, we had an hour-long discussion with Kathy's and mine students.


8/2006~10/2006: Prof. Selim Jochim from Heidelberg University in Germany joins us I am very glad Selim joins us for 2~3 months and will help us constructing the experiments. I know Selim since 2003 and am very happy he can come here and discuss various ideas with us on cold atoms and moleucles.


8/1/2006~8/3/2006: Policy meeting on Quantum Optics and Cold Atoms in Shanghai Invited by CAS Shanghai branch, SIOM and ECNU, I attained the meeting to discuss future research on quantum optics and cold atoms in Shanghai. After the meeting, I visited the impressive experiments in ECNU led by Prof. Ma and Prof. Yin.


6/18/2006~6/23/2006: Gordon Research Conference on Correlated Electron Systems Invited by Prof. Seamus Davis, I went to GRC in Mount Holyoke College in South Hadley, MA and gave a talk on "Collective and single particle excitations of a strongly interacting Fermi gas"


6/14/2006~6/16/2006: Meeting on Strong Correlations in Fermi systems, Invited by Prof. Chris Pethick, I went to Nordita and the Niels Bohr Institute, Copenhagen, Denmark and gave one talk for Rudi on "Precision collective excitation measurements in the BEC-BCS crossover regime" and one on "Pairing Gaps in the BEC-BCS crossover regime".


5/30/2006~6/4/2006: VIST NIST Rudi and I went to NIST to work on our review paper with Paul Julienne and Eite Tiesinga.


5/25/2006: Our paper (cond-mat/0603607) accepted by Physical Review Letters This paper shows a new application of cold atoms and molecules. Victor and I found that cold collision properties can be extremely sensitive to the Strong interaction to Electromagnetic interaction ratio. In particular, for cesium atoms near a narrow Feshbach resonance, a small change of the ratio by 1 part per trillion (10^-12) can lead to a 0.1%~10% change in the scattering length.


5/23/2006: Visit Argonne Invited by Dr. John Schiffer, I gave a talk at Argonne National laboratory on Efimov states.


5/16/2006~5/20/2006: DAMOP meeting Chen-Lung and I attained the meeting. I presented a talk on the "Energy Structure of Feshbach and Efimov Molecules" and chaired an inivited session on "Ultracold molecules". 5/7/2006: OCPA Outstanding Young Researcher Award. It is my great honor to receive the OYRA award from the Oversea Chinese Physics Association.


5/4/2006: Prof. Christopher Monroe visited us. Prof. Monroe from University of Michigan gave a fascinating talk on "Quantum Network and Ion trap quantum computer" in our physics colloquium.


4/23/2006~4/25/2006: Visit Ohio State University Prof. Jason Ho invited me to give a talk on the Efimov state. I discussed with him, Prof. Eric Braaten, Prof. Greg Lafyatis, Prof. Mohit Randeria, Roberto Diener and Hui Zhang on many interesting topics we can study in the future.


4/13/2006: Prof. Moses Chan visited us. Prof. Chan gave a fascinating talk "Can Solid be a superfluid?" in our physics colloquium.


4/7/2006: Visit Purdue University I visited Prof. Jiangping Hu at the Purdue University and gave a talk on the Efimov state. I knew Jiangping since I was a graduate student.


4/3/2006~4/4/2006: Prof. Victor Gurarie visited us. Prof. Victor Gurarie gave a talk at the JFI colloquium on "Fermi gases with Feshbach resonant interactions". He visited our lab and we had long interesting discussions on future Fermi gas experiments.


3/27/2006: New paper Prof. Victor Flambaum and I wrote this paper, "Enhancement of variation of fundamental constants in ultracold atom and molecule systems near Feshbach resonances", cond-mat/0603607. 3/20/2006: Dr. Yuh-Lin Wang visited us. Dr. Yuh Lin Wang is the Director of the Institute of Atomic and Molecular Sciences (IAMS) in Taiwan and is also an alumni of Univ. of Chicago.


3/16/2006: Alfred P. Sloan fellowship It is my honor to receive the fellowship from the Alfred P. Sloan Foundation. Wendy Zhang also got the fellowship, see here.


3/16/2006: "Evidence for Efimov quantum states" on Nature magazine When three identical bosons interact, a set of universal three-body bound states are predicted in the quantum threshold regime (meaning at very low temepratures). These states, called Efimov states, were predicted in 1970 and are now evidenced in the Innsbruck expeirment. More details on our paper and the Efimov physics are here.


3/12/2006 ~ 3/17/2006: APS March meeting I chaired the focus session on "Strongly interacting Fermi gases and BCS-BEC crossover" on 3/13 and gave a contributed talk on "Mean-field model on condensates in the BEC-BCS crossover."


3/8/2006: Discussion with Prof. Wolfgang Ketterle from MIT Prof. Wolfgang realized Bose-Einstein condensation of sodium atoms in 1995 and won the Nobel prize in 2001. His groups in MIT have been extremely productive over the past decade and today he reported exciting news from his Na, Rb and Li experiments in a special seminar talk. In the afternoon, we had two informal discussion sessions with him. Students from my and Kathy's group have the chance to talk to him and ask him about the technical details of the experiment. We also presented to him the progress of our current research and future research direction. He also visited our laboratory in CIS and the new apparatus we are building with much interest.


3/7/2006: EXPERIMENT PROGRESS: Reference laser control Reference laser is the most critical laser in our setup which provides the absolute frequency reference for all the other trapping and cooling lasers. After working on this laser for quite some time, we now successfully set up a polarization spectroscopy based on two photo-diodes. Near a hyperfine transition, we observe signal varies dispersively over a range of 40MHz with a signal-to-noise of >200. A stability of ~200kHz is deduced, which is sufficiently small compared to the natural linewidth of 5MHz. Further inprovements are in progress.


3/7/2006: I gave a JFI colloquium talk on ultracold molecules and the Efimov state Our paper in Nature will be published on 3/16/2006.


3/2/2006: Prof. Gordon Baym from UIUC visited us One of Prof. Gordon Baym's many interests is on degenerate Fermi gases, in particular, its relevance to quark-gluon plasma. At sufficiently high temperatures, the up quarks and down quarks inside the nucleus or neutron stars are freed and strongly interact with each other via gluon exchange. Since quarks are fermions, this system might be simulated by strongly interacting fermionic atoms. I learned quite a bit from talking to Gordon everytime I meet him. In the afternoon, he gave a colloquium talk about the story of Bohr and Heisenberg, both of them have decisive influence in physics and in "atomic sciences".


2/24/2006~2/27/2006: CIAR UltraCold Matter workshop in Banff, Alberto Prof. Allan Griffin invited me to the workshop supported by the Canadian Institute for Advanced Research. Several Canadian experiment groups, especially the one led by Joseph Thywissen, reported interesting results on degenerate quantum gases. Many invited speakers also showed exciting prospects of cold atom research. I am very glad to meet many old friends here, in particular, Allan, Christopher Salomon, Gora, Jason, Jeff, Florian and Henning. I gave the last talk on the Feshbach molecule structure and the Efimov state on Sunday. In the aftenroon, I went hiking with and talked to Christopher, Kirk, Florian, Henning... Everybody is working on a new project! The second day, 2/27, Tony, Jason, Brian and I took the same flight back to Chicago. The flight was seriously delayed for 4 hours. Among all the anxiously-waiting passengers, four physicists were having a good time chatting.


2/14/2006 and 2/16/2006: Prof. Jun Ye visited us Prof. Ye from JILA, NIST and Univ. of Colorado leads one of the most productive groups in AMO which conducts SEVERAL ground braking experiments in frequency combs, cooling and trapping cold molecules and atomic frequency standard, to name a few. We are very happy he came here and give two colloquium talks, one at the JFI and one in the physics department. In his talks, he showed the amazing link between the ultra-precise laser spectroscopy to the complex and fast dynamics of molecules. We had very interesting discussions on possible experiments on ultracold alkali atoms and molecules. I think cold molecules will be far more useful than people imagine nowaday.


2/9/2006~2/10/2006: MRSEC site visit Being part of the Seed Project in the Chicago MRSEC with Kathy' group, our group prepared a poster and a short presentation on our research direction. The director Heinrich Jaeger did a great job to coordinate this site visit. Although very few people came to our poster, I strongly believe research on cold atoms will provide new insights into important issues in many-body systems, condensed matter and possibly material sciencel. The reason is that cold atoms are clean, extremely well characterized, free from impurity, and can be confined to simulate strongly correlated or interacting electroncs in condensed matter, fermions in nano-particles, nucleons in atomic nucleus...


2/2/2006~2/8/2006: Visit NIST and University of Maryland I am very glad to meet and talk to Paul Julienne, Eite Tiesinga and Rudolf Grimm about our paper. We had discussions for a few days on its structure and how we share the tasks to finish it. At NIST, we visited several exciting experiments of Bill Phillips's on Rb and Na BECs, Jabez's on Er and Carl Williams's on "GHz quantum teleportation". At the university of Maryland, the expeirments on cold plasma, cold atoms and the superconductor-based quantum manipulations are extremely interesting. Rudi gave an impressive talk on strongly interacting Fermi gas and on Efimov state at their new Joint Quantum Institute. In this trip, I am particular happy to see Rudi and Adam Black, who is now a postdoc in Bill's group. Rudi and I went to a pretty good Korean/Japanese restaurant on 2/7 and I am happy to hear from him that all the Innsbruck guys are doing very well.


1/31/2006: CM-AMO Sesminar Talk at the University of Michigan Prof. Luming Duan and Prof. Michal Zochowski invited me to give a talk on the ultracold molecules and Efimov states. I also visited the labs of Prof. Christopher Monroe and of Georg Raithel. Their experiments on photon-atom entangelement and on quantum gases on the chip are very interesting. I also discussed with Luming on several ideas in Fermi and Bose systems. After the talk, they invited me to a very nice Chinese restaurant. I wish there is also a good Chinese restaurant around U. of Chicago.


1/15/2006~1/21/2006: Aspen Physics Workshop on Strong Correlations in Ultra-Cold Fermi Systems I will be attending the first cold atom meeting in 2006 in Aspen. Obvioiusly research on ultracold Fermi gas near resonances is one of the hottest topics these days. In particular, Cooper pairing and fermionic superfluidity, universally existing in degenerate Fermi systems with attratctive interactiions, can now been investigated with unprecidented details and wide range of parameters. I look forward to hearing more recent progress on ultracold Fermi and Bose gases. However, I wish it is not too cold in Aspen...