The 7Li＋ ion is one of the most important candidates for verifying QED theory and obtaining the precise value of the fine-structure constant ~. However, direct laser cooling of trapped Li＋ ions will lead to strong b...The 7Li＋ ion is one of the most important candidates for verifying QED theory and obtaining the precise value of the fine-structure constant ~. However, direct laser cooling of trapped Li＋ ions will lead to strong background fluorescence which will influence the spectrum detection. The sympathetic cooling technique is a good choice to solve the problem. In this work, we report sympathetic cooling of 7 Li＋ ions to few mK using 40Ca＋ ions in a linear Paul trap. A mixed ion crystal of 40Ca＋ ions and 7Li＋ ions are obtained. We also analyze the motion frequency spectra of pure 40 Ca＋ ions and mixed ions.展开更多
基金Supported by the National Basic Research Program of China under Grant No 2010CB832803the National Natural Science Foundation of China under Grant Nos 11004222 and 91121016the Chinese Academy of Sciences
文摘The 7Li＋ ion is one of the most important candidates for verifying QED theory and obtaining the precise value of the fine-structure constant ~. However, direct laser cooling of trapped Li＋ ions will lead to strong background fluorescence which will influence the spectrum detection. The sympathetic cooling technique is a good choice to solve the problem. In this work, we report sympathetic cooling of 7 Li＋ ions to few mK using 40Ca＋ ions in a linear Paul trap. A mixed ion crystal of 40Ca＋ ions and 7Li＋ ions are obtained. We also analyze the motion frequency spectra of pure 40 Ca＋ ions and mixed ions.
