Hannover 2020 – wissenschaftliches Programm

Die DPG-Frühjahrstagung in Hannover musste abgesagt werden! Lesen Sie mehr ...

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

A: Fachverband Atomphysik

A 11: Attosecond physics II

A 11.6: Vortrag

Dienstag, 10. März 2020, 15:30–15:45, f107

Imprinting orbital angular momentum onto a propagating matter wave — •Jonas Wätzel and Jamal Berakdar — Martin-Luther-Universität Halle-Wittenberg, Institut für Physik, Halle (Saale)

Recently, the transfer of orbital angular momentum (OAM) to a bound electron by absorbing photons of an optical vortex was proven experimentally [1]. In contrast, the vortex-matter interaction in the case of a propagating photoelectrons is debatable. Indeed, this amounts to transferring the phase information of a classical electromagnetic wave, defined within several hundreds of nanometers, to an ensemble of quantum particles with an extent of few angstroms. In this talk, I present experimental and numerical results of the two-color photoionization of an extended sample of He atoms. Surprisingly, we found that the carried OAM of the IR probe field can be transferred coherently to a photoelectron liberated by an XUV FEL laser pulse. Remarkably, the imprinted phase information survives the averaging over the ensemble of He atoms out to macroscopic distances, where the signal is observed. Our results point to the occurrence of non-dipolar transitions initiated by the IR vortex field, which are inaccessible by one-photon processes driven by conventional unstructured light waves. Based on our predictions, new electron spectroscopy methods and qualitatively new analytical tools can be constructed.

[1] Schmiegelow, C. T. et al. "Transfer of optical orbital angular momentum to a bound electron" Nat. Commun. 7, 12998 (2016).