Speaker
Description
The three-dimensional momentum distribution of photoelectrons is determined by conservation laws embodied in the selection rules and depends on the state of the ionising light fields. The process of high harmonic generation, allows for the creation of light pulses of attosecond duration [1, 2], and the measurement of photoelectron momentum distributions following from the interaction with these, is an important tool for gaining insight in the ultrafast dynamics of light-matter interaction. Recent developments and proposals in the tailoring of the polarisation and spatial properties of such attosecond pulses [3, 4, 5, 6] opens new possibilities for using light fields of exotic configurations in photoionisation experiments, further motivating the improvement of methods for understanding and analysing complex photoelectron momentum distributions. Here, we present a method, which consists both of theoretical simulations of three-dimensional photoelectron distributions, and of an algorithm for decomposing an unknown distribution in a coherent sum of spherical harmonics, with the aim of determining the angular momentum quantum numbers. The theoretical simulation is based on the strong field approximation, and takes as input light fields of a specified configuration, encompassing the number of pulses, their polarization, carrier-to-envelope phase, and the delay between them. This enables investigations of the effect of different features of the light field on the photoelectrons. We intend to demonstrate that this double-sided mathematical tool is robust, within limitations, in the characterisation of photoelectron momentum distributions.
References
[1] P B Corkum, Phys. Rev. Lett. 71, 1994 (1993)
[2] P Antoine et al., Phys. Rev. Lett., 77 1234 (1996)
[3] J M N Djiokap et al., Phys. Rev. Lett., 115, 113004 (2015)
[4] Rego, L. et al., Science, 364, 1253 (2019)
[5] Ayuso, D. et al., Nat. Photonics, 13, 866 (2019)
[6] Habibovi´c, D. et al., Nat. Rev. Phys., 6, 663 (2024)
