Investigation of the nonlinear CPT spectrum of <sup>87</sup>Rb and its application for large dynamic magnetic measurement<xref rid="cpb_26_6_064203_fn1" ref-type="fn">*</xref> <fn id="cpb_26_6_064203_fn1"> <label>*</label> <p>Project supported by the National Natural Science Foundation of China (Grant No. 61473166) and China Postdoctoral Science Foundation (Grant No. 014M560958).</p> </fn>

Investigation of the nonlinear CPT spectrum of ⁸⁷Rb and its application for large dynamic magnetic measurement* *

Project supported by the National Natural Science Foundation of China (Grant No. 61473166) and China Postdoctoral Science Foundation (Grant No. 014M560958).

Xu Chi^{1, 2}, Wang Shi-Guang^{2, 3}, Hu Yong^{2, 3}, Feng Yan-Ying^{2, 3, †}, Wang Li-Jun^{1, 2, 3, ‡}

(color online) (a) Checking of the linear relationship given by Eq. (3). The squares and dots represent the frequency shift vs external magnetic field B of the two peaks in group N = 0, respectively and the triangles represent the frequency difference between the two peaks. The red line is the linear fit which shows a good agreement with Eq. (3). (b) Effective magnetic noise density spectrum. The data above shows the noise performance of the measurement based on the nonlinear split of group N = 0 in the double modulation loop-lock operation (ii), compared with an operation in the same condition but without magnetic shielding (i). The plot (iii) shows the electric noise of the system. The data is all normalized to 1Hz bin.