Gong Ting, Ji Zhonghua, Du Jiaqi, Zhao Yanting, Xiao Liantuan, Jia Suotang
Opt Express. 2021 Jan 18;29(2):1558-1565. doi: 10.1364/OE.411249.
We demonstrate measurement of the permanent electric dipole moment (EDM) of RbCs molecules in the absolute vibrational ground state by microwave (MW) coherent spectroscopy. The rotational states of the considered molecules, which are formed from short-range photoassociation of mixed cold atoms, are nondegenerated under external electric field. To measure the EDM based on electric-field-induced shifts of the sublevels of XΣ(v = 0, J = 1) rotational state, we utilized a MW coherent spectroscopy, which has a higher resolution than depletion spectroscopy and one-photon MW spectroscopy and can also eliminate the influence from Stark shift of the excited state existing in both spectroscopies above. In order to acquire accurate electric intensity, electromagnetic induced transparency spectroscopy of Rb Rydberg atoms is used to implement the calibration. The permanent EDM of RbCs molecules is finally determined to be 1.266(15) D, which agrees with the theoretical calculations and is comparable with the value of its isotopic molecule.
我们通过微波（MW）相干光谱法展示了对处于绝对振动基态的RbCs分子永久电偶极矩（EDM）的测量。所考虑的分子由混合冷原子的短程光缔合形成，其转动状态在外部电场下是非简并的。为了基于XΣ（v = 0，J = 1）转动状态子能级的电场诱导频移来测量EDM，我们采用了一种MW相干光谱法，它比耗尽光谱法和单光子MW光谱法具有更高的分辨率，并且还可以消除上述两种光谱法中存在的激发态斯塔克频移的影响。为了获得精确的电场强度，利用Rb里德堡原子的电磁诱导透明光谱法进行校准。最终确定RbCs分子的永久EDM为1.266(15) D，这与理论计算结果相符，并且与其同位素分子的值相当。
