Floquet-engineered nondispersive wave packets in helium under combined periodic and static fields

TL;DR

This paper demonstrates the numerical discovery of nondispersive, localized two-electron wave packets in helium under combined periodic and static fields, using advanced spectral and Floquet methods.

Contribution

It introduces a novel numerical approach to observe nondispersive wave packets in a three-dimensional helium system with combined fields, revealing long-lived Floquet states.

Findings

Identification of nondispersive wave packets following classical trajectories

Observation of long-lived Floquet states from near-resonant couplings

Use of Coulomb-Sturmian functions with Floquet theory and complex scaling

Abstract

We report the numerical observation of two-electron nondispersive wave packets in fully three-dimensional helium subjected to a linearly polarized monochromatic field. These localized quantum states follow periodic trajectories of the classical three-body Coulomb system without dispersion. The system is modeled using a spectral configuration interaction approach based on Coulomb-Sturmian functions, combined with Floquet theory and complex scaling. The resulting quasienergy spectrum reveals the existence of long-lived Floquet states arising from near-resonant coupling between frozen planet configurations.