Local dynamics in high-order harmonic generation using Bohmian trajectories

TL;DR

This paper explores high-order harmonic generation through Bohmian mechanics, revealing that the core's innermost trajectory dominates the spectra and is influenced by the wavefunction's phase and non-local effects.

Contribution

It introduces a Bohmian-mechanical perspective to high-order harmonic generation, linking core trajectories to classical models and quantum phase effects.

Findings

Inner Bohmian trajectory dominates harmonic spectra

Wavefunction phase influences trajectory dynamics

Peripheral trajectories show phase degradation over time

Abstract

We investigate high-order harmonic generation from a Bohmian-mechanical perspective, and find that the innermost part of the core, represented by a single Bohmian trajectory, leads to the main contributions to the high-harmonic spectra. Using time-frequency analysis, we associate this central Bohmian trajectory to an ensemble of unbound classical trajectories leaving and returning to the core, in agreement with the three step model. In the Bohmian scenario, this physical picture builds up non-locally near the core via the quantum mechanical phase of the wavefunction. This implies that the flow of the wavefunction far from the core alters the central Bohmian trajectory. We also show how this phase degrades in time for the peripheral Bohmian trajectories as they leave the core region.