本文通过双光子光谱测量确定 NaCs 分子中高度混合的 c ³Σ⁺₁ |v=22⟩ ∼ b ³Π₁ |v=54⟩ 态作为 STIRAP 桥接态，实现了向基态转移效率高达 88(4)%，为强偶极 NaCs 分子的多体量子相和单分子高保真探测提供了关键路径。
摘要：
我们提出了一项关于将 NaCs 分子转移到其振转基态的双光子路径研究。从 NaCs Feshbach 分子出发，我们在 900 nm 至 940 nm 波长范围内进行了束缚-束缚激发态光谱测量，覆盖了 c ³Σ⁺、b ³Π 和 B ¹Π 电子态的 30 多个振动态。通过分析转动子结构，我们确定了高度混合的 c ³Σ⁺₁ |v=22⟩ ∼ b ³Π₁ |v=54⟩ 态作为受激拉曼绝热通道（STIRAP）的高效桥接态。我们展示了向 NaCs 基态的转移效率高达 88(4)%。高效转移对于实现强偶极 NaCs 分子的多体量子相以及单分子的高保真探测至关重要，例如在光晶格中的自旋物理实验和光镊阵列中的量子信息实验中。
英文摘要：
We present a study of two-photon pathways for the transfer of NaCs molecules to their rovibrational ground state. Starting from NaCs Feshbach molecules, we perform bound-bound excited state spectroscopy in the wavelength range from 900~nm to 940~nm, covering more than 30 vibrational states of the $c \, ^3Σ^+$, $b \, ^3Π$, and $B \, ^1Π$ electronic states. Analyzing the rotational substructure, we identify the highly mixed $c \, ^3Σ^+_1 \, |v=22 \rangle \sim b \, ^3Π_1 \, | v=54\rangle$ state as an efficient bridge for stimulated Raman adiabatic passage (STIRAP). We demonstrate transfer into the NaCs ground state with an efficiency of up to 88(4)\%. Highly efficient transfer is critical for the realization of many-body quantum phases of strongly dipolar NaCs molecules and high fidelity detection of single molecules, for example, in spin physics experiments in optical lattices and quantum information experiments in optical tweezer arrays.
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