The survival of coherent wavepacket motion during internal conversions is observed in relatively large molecules, N-methyl morpholine and N-ethyl morpholine, where standard models imply fast decoherence in a statistical limit. Optical excitation in the region of 194 to 230 nm excites the molecule to 3s or 3p Rydberg states, launching a wavepacket motion in the umbrella mode of the tertiary amine chromophore. In the short wavelength range, <214 nm, the molecules are excited to the 3p Rydberg state, which decays by internal conversion on a time scale of about 100 fs to the lower-lying 3s Rydberg state. Time-resolved photoionization photoelectron experiments reveal that the coherent wavepacket motion survives the internal conversion with oscillations continuing in the 3s state for several 650 fs periods before the phase lock is lost due to dephasing into the dense bath of vibrational modes of the molecule.

中文翻译：

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非辐射跃迁中的相干性：Rydberg激发的N-甲基和N-乙基吗啉的内部转化

在相对较大的分子N-甲基吗啉和N中观察到内部转换期间相干波包运动的存活-乙基吗啉，其中标准模型表示在统计极限内快速退相干。在194至230 nm范围内的光激发将分子激发至3s或3p Rydberg态，从而在叔胺发色团的伞形模式下发起波包运动。在小于214 nm的短波长范围内，分子被激发到3p Rydberg态，通过内部转换以大约100 fs的时间尺度衰减到较低的3s Rydberg态。时间分辨的光电离光电子实验表明，相干波包运动在内部转换中得以保留，并且在3s状态下振荡持续了650 fs周期，直到由于移入分子振动模式的密集浴而失去了锁相。