Electron dynamics driven by light pulse derivatives

TL;DR

This paper explores a new light-matter interaction regime where ultrashort pulses induce nonadiabatic electron processes sensitive to the pulse envelope's derivative, revealing unique ionization dynamics.

Contribution

It introduces a novel regime of electron dynamics driven by light pulse derivatives and employs a time-dependent close-coupling approach for detailed analysis.

Findings

Ultrashort pulses can induce nonadiabatic ionization bursts.

Ionization amplitudes differ between the two bursts due to energy redistribution.

The approach provides detailed insight into derivative-driven electron dynamics.

Abstract

We demonstrate that ultrashort pulses carry the possibility for a new regime of light-matter interaction with nonadiabatic electron processes sensitive to the envelope-derivative of the light pulse. A standard single pulse with its two peaks in the derivative separated by the width of the pulse acts in this regime like a traditional double pulse. The two ensuing nonadiabatic ionization bursts have slightly different ionization amplitudes. This difference is due to redistribution of continuum electron energy during the bursts, negligible in standard photo-ionization. A time-dependent close- coupling approach based on cycle-averaged potentials in the Kramers-Henneberger reference frame permits a detailed understanding of light pulse derivative-driven electron dynamics.