English

Dynamics of twisted electron impact ionization of CH4 and NH3 molecule

Atomic Physics 2023-03-07 v1

Abstract

Electron vortex beams (EVB, also known as twisted electron beams) possess an intrinsic orbital angular momentum (OAM) with respect to their propagation direction. This intrinsic OAM represents a new degree of freedom that provides new insights into investigating the dynamics of electron impact ionization. In this communication, we present, in the first-Born approximation (FBA), the angular profiles of the triple differential cross-section (TDCS) for the (e, 2e) process on CH4 and NH3 molecular targets in the coplanar asymmetric geometry. We compare the TDCS of the EVB for different values of OAM number m with that of the plane wave. For a more realistic scenario, we investigate the average TDCS for macroscopic targets to explore the influence of the opening angle {\theta}p of the twisted electron beam on the TDCS. In addition, we also present the TDCS for the coherent superposition of two EVBs. The results demonstrate that the twisted (e, 2e) process retrieves the p-type character of the molecular orbitals, which is absent in the plane wave TDCS for the given kinematics. The results for the coherent superposition of two Bessel beams show the sensitivity of TDCS towards the OAM number m.

Keywords

Cite

@article{arxiv.2303.03216,
  title  = {Dynamics of twisted electron impact ionization of CH4 and NH3 molecule},
  author = {Nikita Dhankhar and Neha and R. Choubisa},
  journal= {arXiv preprint arXiv:2303.03216},
  year   = {2023}
}