[1] Huang Yao,Guan Hua,Gao Kelin,et al. Hertz-level measurement of the 40Ca+4s2S1/2-3d2D5/2clock transition frequency with respect to the SI second through the global positioning system[J]. Phys. Rev. A,2012,85: 030503(R).
[2] Huang Yao,Guan Hua,Gao Kelin,et al. Evaluation of the systematic shifts of a single-40Ca+-ion frequency standard[J]. Phys. Rev. A,2011,84: 053841.
[3] Guan Hua,Liu Qiu,Huang Yao,et al. A 729 nm laser with ultra-narrow linewidth for probing 4S1/2-3D5/2 clock transition of 40Ca+[J]. Opt. Comm.,2011,284(1): 217-221.
[10] National Instruments: M Series Whitepaper[Z]. 2004.
[11] National Instruments: Date Acquisition Basics Manual[Z]. 1996.