Annular billiard dynamics in a circularly polarized strong laser field

TL;DR

This paper models the motion of an electron in a C60 molecule under a circularly polarized laser as an annular billiard, revealing distinct stable trajectories and phase space structures that persist across a wide range of laser intensities.

Contribution

It introduces a classical billiard model for electron dynamics in a molecule under laser fields, identifying robust phase space structures like twistless tori that explain trajectory stability.

Findings

Identifies three distinct electron trajectories in the billiard model.

Demonstrates the persistence of these trajectories across laser intensities from 10^10 to 10^14 W*cm^-2.

Links phase space structures to the stability of electron motion in strong laser fields.

Abstract

We analyze the dynamics of a valence electron of the buckminsterfullerene molecule (C60) subjected to a circularly polarized laser field by modeling it with the motion of a classical particle in an annular billiard. We show that the phase space of the billiard model gives rise to three distinct trajectories: "Whispering gallery orbits", which only hit the outer billiard wall, "daisy orbits" which hit both billiard walls (while rotating solely clockwise or counterclockwise for all time), and orbits which only visit the downfield part of the billiard, as measured relative to the laser term. These trajectories, in general, maintain their distinct features, even as intensity is increased from 10^10 to 10^14 W*cm^-2. We attribute this robust separation of phase space to the existence of twistless tori.