Excitation of atoms in an optical lattice driven by polychromatic amplitude modulation

We investigate the mutiphoton process between different Bloch states in an amplitude modulated optical lattice. In the experiment, we perform the modulation with more than one frequency components, which includes a high degree of freedom and provides a flexible way to coherently control quantum states. Based on the study of single frequency modulation, we investigate the collaborative effect of different frequency components in two aspects. Through double frequency modulations, the spectrums of excitation rates for different lattice depths are measured. Moreover, interference between two separated excitation paths is shown, emphasizing the influence of modulation phases when two modulation frequencies are commensurate. Finally, we demonstrate the application of the double frequency modulation to design a large-momentum-transfer beam splitter. The beam splitter is easy in practice and would not introduce phase shift between two arms.Comment: 11pages, 7 figure

Evaluation on Integrated Innovation Capability of Regions Based on Principal Component Analysis

The main carriers of national innovation capacity are the regions which gather the technology, economy, and culture, and the strength of regional innovation capacity indicates the strength of the national innovation capability, so the key to the improvement of the national innovation capacity is to enhance the innovation capacity of every region. Using statistics and statistical software SPSS V17.0 Statistics for principal component analysis, and to analyze and sort the innovation capability for our country’s 15 provinces and municipalities, evaluate the results and put forward policy recommendations related, to provide better ideas for economic development of every region.Key words: comprehensive evaluation; innovation capability of regions; integrated innovation capability; principal component analysis The title, abstract and keywords are being translated into French at present and the French version will be added into the paper later

Long-time nonlinear dynamical evolution for P-band ultracold atoms in an optical lattice

We report the long-time nonlinear dynamical evolution of ultracold atomic gases in the P-band of an optical lattice. A Bose-Einstein condensate (BEC) is fast and efficiently loaded into the Pband at zero quasi-momentum with a non-adiabatic shortcut method. For the first one and half milliseconds, these momentum states undergo oscillations due to coherent superposition of different bands, which are followed by oscillations up to 60ms of a much longer period. Our analysis shows the dephasing from the nonlinear interaction is very conducive to the long-period oscillations induced by the variable force due to the harmonic confinement.Comment: 8 pages, 7 figure