Oscillations in the total photodetachment cross sections of a triatomic anion

TL;DR

This paper derives the photodetachment cross section for a linear triatomic anion, revealing oscillatory behavior dependent on laser polarization and identifying two oscillation frequencies distinct from two-center systems.

Contribution

It provides a new analytical derivation of the cross section for triatomic anions, including orientation effects and comparison with two-center systems, using closed-orbit theory.

Findings

Cross section is strongly oscillatory when laser polarization is parallel to the anion axis.

Oscillation amplitude decreases with increasing angle between laser polarization and the axis.

Two distinct oscillation frequencies are identified in the triatomic anion.

Abstract

The total photodetachment cross section of a linear triatomic anion is derived for arbitrary laser polarization direction. The cross section is shown to be strongly oscillatory when the laser polarization direction is parallel to the axis of the system; the oscillation amplitude decreases and vanishes as the angle between the laser polarization and the anion axis increases and becomes perpendicular to the axis. The average cross section over the orientations of the triatomic system is also obtained. The cross section of the triatomic anion is compared with the cross section of a two-center system. We find there are two oscillation frequencies in the triatomic anion in contrast to only one oscillation frequency in the two-center case. Closed-orbit theory is used to explain the oscillations.