Sturmian-Floquet approach to high-order harmonic generation

TL;DR

This paper introduces a Sturmian-Floquet method for efficiently modeling high-order harmonic generation, revealing how initial atomic coherence and state preparation influence the resulting spectra and offering control strategies.

Contribution

The paper develops a novel Sturmian-Floquet approach for HHG, providing deeper insight into atomic dynamics and coherence effects with potential for controlling harmonic emission.

Findings

Different initial atomic superpositions produce distinct HHG spectra.

The coherence and dipole coupling of initial states significantly affect HHG dynamics.

Initial atomic state preparation can be used to control high-harmonic radiation.

Abstract

We show that the Floquet approach with a Sturmian basis means an efficient description of high-order harmonic generation with monochromatic excitation. This method, although involves numerical calculations, is close to analytic approaches with the corresponding deeper insight into the dynamics. As a first application, we investigate the role of atomic coherence during the process of HHG: as it is shown, different coherent superpositions of initial atomic states produce observably different HHG spectra. For linearly polarized excitation, we demonstrate that the question whether the constituents of the initial superpositions are dipole coupled or not, strongly influences the dynamics. By investigating time-dependent HHG signals, we also show that the preparation of the initial atomic state can be used for the control of the high-harmonic radiation.