Momentum-space crystal in narrow-line cooling of <sup>87</sup>Sr<xref rid="cpb_28_1_013701fn1" ref-type="fn">*</xref><fn id="cpb_28_1_013701fn1"><label>*</label><p>Project supported by the National Natural Science Foundation of China (Grant Nos. 11474282 and 61775220), the Key Research Project of Frontier Science of the Chinese Academy of Sciences (Grant No. QYZDB-SSW-JSC004), and the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB21030100).</p></fn>

Momentum-space crystal in narrow-line cooling of ⁸⁷Sr**

Project supported by the National Natural Science Foundation of China (Grant Nos. 11474282 and 61775220), the Key Research Project of Frontier Science of the Chinese Academy of Sciences (Grant No. QYZDB-SSW-JSC004), and the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB21030100).

Han Jian-Xin^{1, 2}, Lu Ben-Quan¹, Yin Mo-Juan¹, Wang Ye-Bing^{1, 2}, Xu Qin-Fang¹, Lu Xiao-Tong^{1, 2}, Chang Hong^{1, 2, †}

MSC image at various saturation factors and detuning frequencies of the laser at t = 20 ms by EMCCD at an atomic temperature of 5 μK: from top to bottom, the images have saturation factors of 30, 100, and 300; from left to right, the images have detuning frequencies of 120 kHz, 140 kHz, and 160 kHz.