发表机构
Institut de Physique de Rennes, CNRS-Université de Rennes（雷恩物理研究所，法国国家科学研究中心-雷恩大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文首次理论研究了亚稳态氦二聚体与Ne和Ar的超冷碰撞，揭示了极浅势阱和丰富的共振结构，为激光冷却和精密测量提供了基准。
AI 中文摘要
处于亚稳态三重电子态的氦二聚体He$_2(a~^3\Sigma_u^+)$是直接激光冷却和精密测量的有前景的候选体系。涉及He$_2(a~^3\Sigma_u^+)$的相互作用和碰撞在超冷和冷能量域中仍未得到探索。在此，我们首次对He$_2(a~^3\Sigma_u^+)$+Ne范德瓦尔斯复合物的分子间相互作用和碰撞动力学进行了理论研究。对于基电子态$X~^3\mathrm{A}'$，我们采用了自旋限制的耦合簇方法，包含单、双和非迭代三重激发。所得的相互作用势表现出极浅的势阱，深度为4.612 cm$^{-1}$。我们构建了一个三维振动平均势能面。利用该势能面，我们进行了包含He$_2(a~^3\Sigma_u^+)$精细结构能级的全密耦合计算，以研究由Ne诱导的碰撞激发和猝灭。我们分析了低能散射动力学，并模拟了与相互作用势支持的准束缚态相关的共振特征。建立了精细结构守恒跃迁的倾向规则。我们还考虑了He$_2$+Ar碰撞，并将其能量依赖性和共振结构与He$_2$+Ne进行了比较。He$_2$+Ar体系表现出更丰富的共振结构，突显了低能散射对相互作用势和约化质量的敏感性。计算得到的势能面和散射性质为描述He$_2$+Ne范德瓦尔斯复合物提供了可靠的基准，并可能有助于解释未来的实验光谱和碰撞测量。
英文摘要
Helium dimer in its metastable triplet electronic state, He$_2(a~^3Σ_u^+)$, is a promising candidate for direct laser cooling and precision measurements. Interactions and collisions involving He$_2(a~^3Σ_u^+)$ remain unexplored in ultracold and cold energy domains. Here, we present the first theoretical investigation of intermolecular interactions and collision dynamics of He$_2(a~^3Σ_u^+)$+Ne van der Waals complex. For the ground electronic state, $X~^3\mathrm{A}'$, we employ a spin-restricted coupled cluster method with single, double, and noniterative triple excitations. The resulting interaction potential exhibits an extremely shallow well with a depth of 4.612 cm$^{-1}$. We construct a three-dimensional vibrationally averaged potential energy surface. Using this surface, we perform full close-coupling calculations including fine-structure levels of He$_2(a~^3Σ_u^+)$ to investigate collisional excitation and quenching induced by Ne. We analyze the low-energy scattering dynamics and model resonant features associated with quasi-bound states supported by interaction potential. Propensity rule for fine-structure conserving transitions is established. We additionally consider He$_2$+Ar collisions and compare their energy dependence and resonance structure with those of He$_2$+Ne. The He$_2$+Ar system exhibits a richer resonance structure, highlighting the sensitivity of low-energy scattering to interaction potential and reduced mass. Calculated PES and scattering properties provide a reliable benchmark for description of He$_2$+Ne van der Waals complex and may be useful for interpretation of future experimental spectra and collision measurements.
