Total photoionization cross section of planar helium: scaling laws and collision orbits

Lee, Min-Ho; Byun, Chang Woo; Choi, Nark Nyul; Tanner, Gregor

Abstract

The total photoionization cross section of planar helium has been calculated up to the single ionization threshold I22 of triple P states. The cross section shows chaotic fluctuations as the energy E approaches the double ionization threshold E=0. By analyzing the fluctuating part of the cross section, we show that its amplitude decreases as ?E? mu for E-> 0- as predicted in Byunet al(2007 Phys. Rev. Lett., 98, 113001). The Fourier transform of the fluctuating part reveals peaks at the classical actions of closed triple collision orbits. Furthermore, the relative height of the peaks is consistent with the semiclassical predictions. Our findings underline that the fluctuating part of the photoionization cross section can be described by classical triple collision orbits in the semiclassical limit. These orbits all lie in the collinear eZe subspace, demonstrating that the fluctuations are dominated by the dynamics of this low dimensional phase space.

• Journal Article Type: Article
• Acceptance Date: Aug 8, 2018
• Online Publication Date: Aug 28, 2018
• Publication Date: Sep 28, 2018
• Deposit Date: Oct 18, 2018
• Publicly Available Date: Aug 29, 2019
• Journal: Journal of Physics B: Atomic, Molecular and Optical Physics
• Print ISSN: 0953-4075
• Electronic ISSN: 1361-6455
• Publisher: IOP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 51
• Issue: 18
• Article Number: 185001
• DOI: https://doi.org/10.1088/1361-6455/aad8e2
• Keywords: Atomic and Molecular Physics, and Optics; Condensed Matter Physics
• Public URL: https://nottingham-repository.worktribe.com/output/1174985
• Publisher URL: http://iopscience.iop.org/article/10.1088/1361-6455/aad8e2