Mirror symmetry rupture in double photoionization of endohedrally confined atoms

TL;DR

This paper investigates how the symmetry of double photoionization in helium atoms is affected when confined inside a spherical fullerene, revealing symmetry breaking effects and modifications to the ionization cross section.

Contribution

It introduces a model for endohedral helium in a fullerene, analyzing symmetry rupture and the influence of the fullerene potential on photoionization cross sections.

Findings

Mirror symmetry collapse in the cross section due to electron delocalization.

Higher angular momentum partial waves significantly alter the ionization pattern.

Symmetry breaking effects depend on the well depth of the fullerene potential.

Abstract

We study the double electronic emission by photon impact from He in the center of a spherical fullerene, which is modeled by a square-well shell. This system exhibits a manifold of avoided crossings as a function of the well depth, and present mirror colapses. However, this symmetry is broken in the triple differential cross section due to the delocalization of the He electrons in the initial state. Moreover, the fullerene potential involves higher angular momenta partial waves to be included in the process, which modifies the well-known two-lobe cross section from isolated He.