A shape resonance emerges during the light absorption in many molecules with a gigantic burst amplitude and a lifetime of hundreds of attoseconds. Recent advances in attosecond metrology revealed the attosecond lifetime of the shape resonance. For a heteronuclear molecule, the asymmetric initial state and landscape of the molecular potential would lead to an asymmetric shape resonance, whose effect, however, has not been characterized yet. Here, we employ an attosecond interferometer to investigate the molecular-frame photoionization time delay in the vicinity of the shape resonance of the NO molecule. Driven by photons with energy ranging from 23.8 eV to 36.5 eV, a 150 attosecond difference in the time delay is observed between photoemission from the $\mathrm{N}/\mathrm{O}$ end. Our quantum scattering theoretical simulations reproduce well our experimental findings. It illustrates that the asymmetric time delay originates from the interference between resonant and nonresonant photoionization pathways.

中文翻译：

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分子形状共振中的不对称阿秒光电离

许多分子在光吸收过程中会出现形状共振，具有巨大的爆发幅度和数百阿秒的寿命。阿秒计量学的最新进展揭示了形状共振的阿秒寿命。对于异核分子，分子势的不对称初始状态和景观会导致不对称形状共振，但其影响尚未表征。在这里，我们使用阿秒干涉仪来研究 NO 分子形状共振附近的分子框架光电离时间延迟。在能量范围为 23.8 eV 到 36.5 eV 的光子的驱动下，观察到来自$\mathrm{N}/\mathrm{哦}$结尾。我们的量子散射理论模拟很好地再现了我们的实验结果。它说明非对称时间延迟源于共振和非共振光电离路径之间的干扰。