We experimentally and theoretically demonstrate that electron correlation can cause the bond-length sensitivity of a shape resonance to induce an unexpected vibrational state–dependent ionization delay in a nonresonant channel. This discovery was enabled by a high-resolution attosecond-interferometry experiment based on a 400-nm driving and dressing wavelength. The short-wavelength driver results in a 6.2–electron volt separation between harmonics, markedly reducing the spectral overlap in the measured interferogram. We demonstrate the promise of this method on O₂, a system characterized by broad vibrational progressions and a dense photoelectron spectrum. We measure a 40-attosecond variation of the photoionization delays over the X²Π_g vibrational progression. Multichannel calculations show that this variation originates from a strong bond-length dependence of the energetic position of a shape resonance in the ${\mathrm{b}}^4{\mathrm{\Sigma }}_g^{-}$ channel, which translates to the observed effects through electron correlation. The unprecedented energy resolution and delay accuracies demonstrate the promise of visible-light–driven molecular attosecond interferometry.

中文翻译：

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O2 中电子相关性与形状共振引起的阿秒电离延迟的键长依赖性

我们通过实验和理论上证明，电子相关性可以导致形状共振的键长敏感性，从而在非共振通道中引起意想不到的振动状态相关的电离延迟。这一发现是通过基于 400 nm 驱动和修整波长的高分辨率阿秒干涉测量实验实现的。短波长驱动器在谐波之间产生 6.2 电子伏特的间隔，显着减少了测量的干涉图中的光谱重叠。我们在 O ₂上证明了这种方法的前景，O 2 是一种以广泛的振动级数和密集的光电子能谱为特征的系统。我们测量了 X ² Π _g振动进程中光电离延迟的 40 阿秒变化。多通道计算表明，这种变化源于形状共振能量位置的强键长依赖性。${\mathrm{乙}}^4{\mathrm{\Sigma }}_G^{-}$通道，通过电子相关性转化为观察到的效应。前所未有的能量分辨率和延迟精度证明了可见光驱动的分子阿秒干涉测量的前景。