Since 1998, entered into an innovative, we have built nicer cooperative relationships with more than 20 internationally renowned atomic and molecular research institutes, including National Institute of Standards and Technology (NIST), Joint Institute of Laboratory Astrophysics (JINA), Stanford University, U.S., National Physical Laboratory (NPL), Oxford University, Imperial College of Science and Technology, UK., and Institute of Atomic and Molecular Sciences Academia Sinica, Taiwan. Though full cooperation, we have made outstanding achievements in Atomic and Molecular Physics and Applications. The results cover many disciplines, including cold atomic physics, atomic and molecular external field effect, atomic frequency standard, quantum information, etc. We have come out with 14 papers on top international journals of physics (PRL), made 49 patent applications, gotten 30 patents licensing. We have held the First and the Third International Symposiums on Cold Atom Physics, and won international partners project funding for creative team on cold atom physics and quantum optics by Chinese Academy of Sciences and the State Foreign Experts Bureau. Small rubidium atomic clock developed by our institute has succeeded in achieving 20 million yuan by patent licensing, expected economic benefits up to 125 million yuan.
1、Matter-wave self-imaging by atomic center-of-mass motion induced interference (PRL, 2007, 93:083604)
Working together with NIST, we have demonstrated a new matter-wave self-imaging effect by experimentally investigating the scatter characteristic of BEC in a standing wave field. We show that non-negligible atomic center-of-mass motion and an instantaneous Doppler shift can drastically change the condensate momentum distribution, resulting in a periodic collapse and the recurrence of condensate diffraction probability as a function of the stationary light-field pulsing time. The observed matter-wave self-imaging is characterized by an atomic center-of-mass motion induced population amplitude interference in the presence of the light field that simultaneously minimizes all high (n≧1) diffraction orders and maximizes the zeroth diffraction component. This is the first inland BEC experimental work appeared in PRL.
2、Inelastic two-wave mixing to achieve a state of destruction under the quantum interference phenomenon (PRL, 2007, 93:083604)
In cooperation with NIST, researchers studied quantum interference of two single-photon excitation path used rubidium atoms at room temperature. Studies have shown that, in the corresponding "strong storage - weak release" of the light field, non-elastic double-wave mixed state under the two single-photon excitation path to destruction of the existence of quantum interference. Since the destruction of interference depends on the mixed-wave generation and dissemination, and therefore a substantially different with the conventional electromagnetic induction through.The study also shows that the largest atom interferometer does not normally result in the largest wave mixing conversion efficiency, the result is the exactly the opposite understanding with traditional point.
3、Demonstrated the establishment of light / dark super-slow-light soliton in cold atom medium (PRL, 2004, 93:143904)
Cooperating with the NIST of United States , through theoretical simulation and numerical calculations, researchers found that in the approximation conditions, the bright /dark super-slow-light soliton has significant propagation characteristics in the atomic medium of high-resonance characteristics. The work proposed the framework of cold atomic gas super-slow-light soliton theoretical for the first time in the international arena, and will have widespread impact in Condensed Matter Physics research and application technology.
4、BEC of the particle - hole pairs achieved in theory (PRL, 2004, 93:120406)
Cooperating with German Max - Planck physics research of complex systems , for ultra-cold atomic Fermi gases in optical lattices，researchers have studied and explored the atomic - hole pairs Bose - Einstein condensation. Analysis shows that in the limit of strong repulsion, the dynamic of the atom - hole pairs can be described by hard-core Bose-Hubbard model. By controlling the strength of constraining laser to decrease or increase the depth of binding potential, insulation - superfluid or density waves - superfluid phase transition can be caused, thus demonstrating the atom - hole pairs can form a novel Bose - Einstein condensation.Physics News Updates believes that this work will promote the study of quantum gases under extreme conditions which is of great concern in the current; at the same time, similar to the light-emitting mechanism of electron - hole pairs, atom - hole pair model provides a novel non - linear light-emitting mechanism.
Bio-magnetic resonance spectroscopy and imaging
Nuclear magnetic resonance (NMR) spectroscopy is an important research tool to study the chemical composition, molecular structure and dynamics, it’s widely used in cutting-edge of scientific research. There are an academician of Chinese Academy of Sciences, 4 winners of National Outstanding Youth Fund, 6 winners of Chinese Academy of Sciences Hundred Talents in bio-magnetic resonance innovations of our institute, associate with other international top talent of bio-magnetic resonance spectroscopy and imaging who from Yale University, the National High Field Laboratory, National University of Singapore, Lille University of Technology of France, Taiwan sun yet-sen university to form a strong international research team. The past five years, the international team published more than 270 papers in Science, PNAS, JACS, PRL and other SCI articles, which was cited more than 1470 times; The team invited to write more than 13 review or feature articles for Modern Magnetic Resonance; We have successfully completed the Fund major international cooperation projects "using NMR relaxation technology research related to fatty acid binding protein dynamics and function", successfully held the "second session of the magnetic resonance of new technologies - International Symposium on NMR of biological macromolecules", "2006 China-French Solid-NMR Symposium and Solid-NMR technical training "," Second Cross-Strait Academic Conference on Magnetic Resonance ", etc. The team states an important position in the international field of spectroscopy study.
1、The sub-space location of the protons in Phosphotungstic acid and mechanism of acid strength is successfully revealed (JACS, 2005, 127:18274)
In cooperation with the University of Virginia, using new technologies of solid state NMR, through the accurate measurement of interactions between probe molecules of acetone and the acidic proton in phosphotungstic acid and the nuclear distance, combined with quantum chemical calculations, we confirm the exact location of a variety of acidic protons in the phosphate tungsten acid, movement characteristics and acid strength, completely solved this dispute issue for a long time. The results showed that: anhydrous phosphotungstic acid is much stronger than micro porous molecular sieves, and the protons in different positions, acid strength is also different. The research results provide an important basis for modification of solid acidic materials and industrial applications.
2、Successfully established the new method for the determination of protein side chain dynamics （JACS, 2006, 128:5073）
In cooperation with the National University of Singapore, the branched-chain dynamics of protein folding and interaction have been in-depth researched and developed a new protein dynamics research methods that can be used to obtain the dynamic characteristics from the methyl group dipole - dipole cross - relaxation rate of branched-chain, while avoiding the complex 2H tag in conventional method. At the same time, researchers using the new method to study the dynamics of methyl group in branched chain of human intestinal fatty acid protein binding oleic acid before and after, the results show that activity of the methyl near the binding sites significantly reduced, while other parts had no significant changes.
3、Successfully established a new method of protein-protein interaction dynamics using NMR analysis (JACS, 2008, 130:2432)
In cooperation with the National University of Singapore, using nuclear magnetic resonance (NMR) technology, gain new progress in kinetic measurement methods at microseconds - millisecond time range. They proposed a new phase circulation mechanism which could effectively eliminate the resonance signal of bias could not completely reunited in multiple spin-echo (CPMG), so as to effectively reduce the frequency offset, RF non-uniform, scalar coupling, cross-relaxation and other effects, so that the order of the kinetics of protein millisecond accuracy greatly improved, provided new technologies for accurate determination the slow exchange. Protein-protein interaction dynamics research has contributed to a systematic understanding of the relationship between protein structure and function, and provide theoretical and experimental basis for drug target discovery and drug design.
4、Reveals the important intestinal flora involved in the metabolism (PNAS, 2008, 105:2117)
In cooperation with Imperial College of the United Kingdom, after nearly three years of joint research, using bacterial DNA fingerprinting and genomic sequencing technology such as genomic markers, a comprehensive in-depth characterization of the intestinal flora of seven Chinese members have been painted, preliminary findings of the intestinal flora and some metabolites in human urine showed a significant correlation, suggesting that the intestinal bacteria is particularly important on human health. The new research results are useful for fully understand how intestinal flora affects the metabolism of the body, such as how to transform food into energy, how to maintain cell survival and so on.