Due to its low sensitivity to blackbody radiation, neutral mercury is a good candidate for the most accurate optical lattice clock. Here we report the observation of cold mercury atoms in a magneto-optical trap （MOT...Due to its low sensitivity to blackbody radiation, neutral mercury is a good candidate for the most accurate optical lattice clock. Here we report the observation of cold mercury atoms in a magneto-optical trap （MOT）. Because of the high vapor pressure at room temperature, the mercury source and the cold pump were cooled down to 40℃ and 70 ℃, respectively, to keep the science chamber in an ultra-high vacuum of 6×10^-9 Pa. Limited by the power of the UV cooling laser, the one beam folded MOT configuration was adopted, and 1.5×10^5 Hg-202 atoms were observed by fluorescence detection.展开更多
We numerically analyze the dynamic behavior of Bose–Einstein condensate(BEC)in a one-dimensional disordered potential before it completely loses spatial quantum coherence.We find that both the disorder statistics and...We numerically analyze the dynamic behavior of Bose–Einstein condensate(BEC)in a one-dimensional disordered potential before it completely loses spatial quantum coherence.We find that both the disorder statistics and the atom interactions produce remarkable effects on localization.We also find that the single phase of the initial condensate is broken into many small pieces while the system approaches localization,showing a counter-intuitive step-wise phase but not a thoroughly randomized phase.Although the condensates as a whole show less flow and expansion,the currents between adjacent phase steps retain strong time dependence.Thus we show explicitly that the localization of a finite size Bose–Einstein condensate is a dynamic equilibrium state.展开更多
基金Project supported by the Research Project of Shanghai Science and Technology Commission, China (Grant No. 09DJ1400700)the National Natural Science Foundation of China (Grant Nos. 10974211 and 11104292)the National Basic Research Program of China (Grant No. 2011CB921504)
文摘Due to its low sensitivity to blackbody radiation, neutral mercury is a good candidate for the most accurate optical lattice clock. Here we report the observation of cold mercury atoms in a magneto-optical trap （MOT）. Because of the high vapor pressure at room temperature, the mercury source and the cold pump were cooled down to 40℃ and 70 ℃, respectively, to keep the science chamber in an ultra-high vacuum of 6×10^-9 Pa. Limited by the power of the UV cooling laser, the one beam folded MOT configuration was adopted, and 1.5×10^5 Hg-202 atoms were observed by fluorescence detection.
基金Supported by the National Natural Science Foundation of China under Grant No.10974211the National Basic Research Program of China under Grant No.2011CB921504the Research Project of Shanghai Science and Technology Commission under Grant Nos.09DJ1400700 and 10DJ1400600.
文摘We numerically analyze the dynamic behavior of Bose–Einstein condensate(BEC)in a one-dimensional disordered potential before it completely loses spatial quantum coherence.We find that both the disorder statistics and the atom interactions produce remarkable effects on localization.We also find that the single phase of the initial condensate is broken into many small pieces while the system approaches localization,showing a counter-intuitive step-wise phase but not a thoroughly randomized phase.Although the condensates as a whole show less flow and expansion,the currents between adjacent phase steps retain strong time dependence.Thus we show explicitly that the localization of a finite size Bose–Einstein condensate is a dynamic equilibrium state.
