Bond-length dependence of attosecond ionization delays in O<sub>2</sub><sub> </sub>arising from electron correlation to a shape resonanc
ORAL
Abstract
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 separatio 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 photoelec-tron spectrum. We measure a 40-attosecond variation of the photoionization delays over the X2Πg 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 b4Σ−g channel, which translates to the observed effects through electron correlation. The unprecedented energy resolution and delay accuracies demonstrate the prom- ise of visible- light–driven molecular attosecond interferometry.
400- nm driving and dressing wavelength. The short-wavelength driver results in a 6.2–electron volt separatio 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 photoelec-tron spectrum. We measure a 40-attosecond variation of the photoionization delays over the X2Πg 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 b4Σ−g channel, which translates to the observed effects through electron correlation. The unprecedented energy resolution and delay accuracies demonstrate the prom- ise of visible- light–driven molecular attosecond interferometry.
*Work by DH, TB and HJW was supported by ETH and the Swiss National Science Foundation under project 200020\_204928. Work by RRL was supported by the U.S. Department of Energy Office of Basic Energy Sciences, Division of Chemical Sciences, Biosciences, and Geosciences, under Contract No. DE-AC02-05CH1 1231. Calculations at LBNL used the Lawrencium computational cluster resource provided by the IT Division at the Lawrence Berkeley National Laboratory.
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Publication: Sci. Adv. 10, ead38100(2024)
Presenters
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Robert Ross Lucchese
- Lawrence Berkeley National Laboratory