Resonant two-photon ionization of helium atoms studied by attosecond interferometry

Summary, in English

We study resonant two-photon ionization of helium atoms via the 1s3p, 1s4p and 1s5p¹P₁ states using the 15^th harmonic of a titanium-sapphire laser for the excitation and a weak fraction of the laser field for the ionization. The phase of the photoelectron wavepackets is measured by an attosecond interferometric technique, using the 17^th harmonic. We perform experiments with angular resolution using a velocity map imaging spectrometer and with high energy resolution using a magnetic bottle electron spectrometer. Our results are compared to calculations using the two-photon random phase approximation with exchange to account for electron correlation effects. We give an interpretation for the multiple π-rad phase jumps observed, both at and away from resonance, as well as their dependence on the emission angle.

• Författare: L. Neoričić; D. Busto; H. Laurell; R. Weissenbilder; M. Ammitzböll; S. Luo; J. Peschel; H. Wikmark; J. Lahl; S. Maclot; R. J. Squibb; S. Zhong; P. Eng-Johnsson; C. L. Arnold; R. Feifel; M. Gisselbrecht; E. Lindroth; A. L’Huillier
• Avdelning/ar: Atomfysik; Fysiska institutionen; Lunds lasercentrum, LLC; LTH profilområde: Avancerade ljuskällor; NanoLund: Centre for Nanoscience; Synkrotronljusfysik; LTH profilområde: Nanovetenskap och halvledarteknologi
• Publiceringsår: 2022-10
• Språk: Engelska
• Publikation/Tidskrift/Serie: Frontiers in Physics
• Volym: 10
• Länkar: http://dx.doi.org/10.3389/fphy.2022.964586
• Dokumenttyp: Artikel i tidskrift
• Förlag: Frontiers Media S. A.
• Ämne: Atom and Molecular Physics and Optics
• Nyckelord: attosecond; attosecond dynamics; photoelectron interferometry; photoionization; photoionization dynamics
• Status: Published
• Projekt: Controlling the photoelectric effect in real-time
• ISBN/ISSN/Övrigt: ISSN: 2296-424X