The light-induced frequency shift (LIFS) of ultracold molecular ro-vibrational levels originates from the strong coupling of the atomic-scattering state and the bound-molecular state. In this paper, we present our experimental determination of the LIFSs of the lowest vibrational levels (ν = 0, 1) in the purely long-range \(0_g^-\) state of ultracold cesium molecules. A high-resolution double photoassociation spectroscopy is developed, which serves as frequency ruler to measure the frequency shifts of the lowest molecular levels for Cs₂. The experimental results are qualitatively consistent with the theoretical expectations.

中文翻译：

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在分子纯长程$$ 0_g ^-$$ 0g-状态下，超冷Cs 2的最低振动水平的光诱导频移

超冷分子旋转振动水平的光诱导频移（LIFS）源自原子散射状态和键合分子状态的强耦合。在本文中，我们介绍了在超冷铯分子的纯远程\（0_g ^-\）状态下最低振动水平（ν = 0，1）的LIFS的实验确定。高分辨率双光缔合光谱学被开发出来，它可以作为频率标尺来测量Cs ₂最低分子水平的频移。实验结果在质量上与理论预期相符。