Assemblies of highly excited Rydberg atoms in an ultracold gas can be set into motion by a combination of van der Waals and resonant dipole-dipole interactions. Thereby, the collective electronic Rydberg state might change due to nonadiabatic transitions, in particular if the configuration encounters a conical intersection. For the experimentally most accessible scenario, in which the Rydberg atoms are initially randomly excited in a three-dimensional bulk gas under blockade conditions, we numerically show that nonadiabatic transitions can be common when starting from the most energetic repulsive Born-Oppenheimer surface. We outline how this state can be selectively excited using a microwave resonance, and demonstrate a regime where almost all collisional ionization of Rydberg atoms can be traced back to a prior nonadiabatic transition. Since Rydberg ionization is relatively straightforward to detect, the excitation and measurement scheme considered here renders nonadiabatic effects in Rydberg motion easier to demonstrate experimentally than in scenarios considered previously.

中文翻译：

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具有随机原子位置的里德堡气体中的非绝热动力学

通过范德华力和共振偶极-偶极相互作用的组合，可以使超冷气体中的高度激发的里德堡原子集合开始运动。因此，由于非绝热跃迁，集体电子里德堡态可能会发生变化，特别是如果配置遇到锥形交叉点。对于实验上最容易获得的场景，在封锁条件下，里德堡原子最初在三维体气体中随机激发，我们从数值上表明，当从能量最高的排斥性波恩-奥本海默表面开始时，非绝热跃迁可能很常见。我们概述了如何使用微波共振选择性激发这种状态，并展示了一种几乎所有里德堡原子碰撞电离都可以追溯到先前的非绝热跃迁的机制。