# Angle-resolved RABBITT: from atoms to molecules

J Joseph, F Holzmeier, D Bresteau, C Spezzani, T Ruchon, J F Hergott, O Tcherbakoff, P D'oliveira, R R Lucchese, J C Houver, et al.

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## To cite this version:

J Joseph, F Holzmeier, D Bresteau, C Spezzani, T Ruchon, et al., Angle-resolved RABBITT: from atoms to molecules. Journal of Physics: Conference Series, 2020, 1412 (7), pp.072002. 10.1088/1742-6596/1412/7/072002. [hal-04460281]

HAL Id: hal-04460281

https://hal.science/hal-04460281v1

Submitted on 15 Feb 2024

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Angle-resolved RABBITT : from atoms to molecules

J Joseph¹*, F Holzmeier¹†, D Bresteau², C Spezzani³, T Ruchon², J F Hergott², O Tcherbakoff², P D'Oliveira², R R Lucchese⁴, J C Houver¹, B Carré² and D Dowek¹

¹ISMO, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Orsay, 91405, France

²LIDYL, CEA, CNRS, Université Paris-Saclay, Gif Sur Yvette, 91191, France

³Elettra-Sincrotrone, Trieste, Basovizza, 34149, Italy

⁴Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720, USA

**Synopsis** We report recent results of photoelectron angular distributions (PADs) for photoionization (PI) of atomic and molecular targets, resolved in the time domain at the attosecond scale, combining electron-ion coincidence momentum spectroscopy and the RABBITT scheme. We propose a unified formalism synthetizing the PAD(θ,τ) results in terms of a reduced set of coefficients.

Combining the XUV-IR RABBITT [1] interferometric technique at the 10kHz Attolab-FAB10 beamline, with electron-ion coincidence momentum spectroscopy, we investigate PADs for atomic (Ar) and molecular (NO, O₂) targets.

In this scheme, an attosecond XUV pulse train ionizes the target and a superimposed IR field with angular frequency ω and delay τ induces continuum-continuum (cc) transitions, generating sidebands (SB) in the photoelectron (PE) spectra. Analysing the 2ω modulation of the SB signal as a function of τ paved the way to studies of PI dynamics in real time, leading to the determination of Wigner time delays τW of the PE wavepacket generated by one-XUV-photon absorption [2]. This requires deciphering, within the atomic time delay τA, the τcc contribution due to the cc transition [3]. Advanced developments address angularly resolved RABBITT studies, with the goal to retrieve Wigner delays as a function of the ejection direction [4-9].

This experiment gives access to the PAD $I_{SB}(\theta, \tau)$, where θ is the emission angle relative to the light polarization P, and to the MFPAD $I_{SB}(\theta_e, \phi_e, \chi, \tau)$ for a molecule oriented at any χ angle relative to P, where $(\theta_e, \phi_e)$ defines the emission direction in the molecular frame (MF). In the RABBITT spectrogram:

$$I_{SB}(\theta, \tau) = A(\theta) + B(\theta) \cos(2\omega\tau + C(\theta))$$

the atomic PE delays τA(θ) relative to τA(0°) are extracted from the C(θ) phase. Here we display an example of measured A(θ) (static) and B(θ) (dynamic) amplitudes for PI of Ar. A unified formalism synthetizing $I_{SB}(\theta, \tau)$ in terms of a

<figure><img src="image_3.png" /><figcaption>**Figure 1** A(θ) and B(θ) for SB16 in XUV+IR PI of Ar. reduced set of coefficients, which allows for generating e.g. the A(θ), B(θ) and C(θ) functions, will be presented. First MFPADs, obtained taking advantage of dissociative PI, will also be reported for PI of NO and compared with MCSCI calculations.</figcaption></figure>

Acknowledgments

We gratefully greet the memory of B Carré, coordinator of Attolab, deceased March 6, 2018. This research was supported by the ANR-10-LABX-0039-PALM, ANR-11-EQPX0005-ATTOLAB, ASPIRE Marie Sklodowska-Curie ITN (H2020 ID: 674960), and Lidex OPT2X-Paris-Saclay.

References

[1] Paul P M et al 2001 *Science* **292** 1689

[2] Klünder K et al 2011 *Phys. Rev. Lett.* **106** 143002

[3] Dahlström J M et al. 2013 *Chem. Phy.* **414** 53

[4] Heuser S et al 2016 *Phys. Rev. A.* **94** 063409

[5] Cirelli C et al 2018 *Nat. Commun.* **9** 955

[6] Bray A W et al 2018 *Phys. Rev. A.* **97** 063404

[7] Vos J et al 2018 *Science* **360** 1326

[8] Hockett P et al 2016 *J. Phys. B. At. Mol. Opt. Phys.* **49** 095602

[9] Baykusheva D and Wörner H J 2017 *J. Chem. Phys.* **146** 124306

<footnote>* E-mail: jennifer.joseph@u-psud.fr</footnote>

<footnote>† E-mail: fabian.holzmeier@polimi.it</footnote>