Attosecond dynamics of light-induced resonant hole transfer in high-order-harmonic generation

TL;DR

This paper investigates how extreme ultraviolet pulses influence high-order harmonic generation in krypton, revealing insights into electron dynamics, hole transfer, and the role of attosecond pulses in controlling inner-shell electron excitation.

Contribution

It introduces a one-dimensional TDCIS model to analyze XUV-assisted HHG and highlights the significance of hole transfer and attosecond control in the process.

Findings

XUV pulses extend the HHG plateau revealing inner-shell electron excitation.

The duration of electron trajectories can be extracted from the HHG spectrum.

Coherent population transfer between inner and outer holes is achievable with attosecond pulses.

Abstract

We present a study of high-order-harmonic generation (HHG) assisted by extreme ultraviolet (XUV) attosecond pulses, which can lead to the excitation of inner-shell electrons and the generation of a second HHG plateau. With the treatment of a one-dimensional model of krypton, based on time-dependent configuration interaction singles (TDCIS) of an effective two-electron system, we show that the XUV-assisted HHG spectrum reveals the duration of the semiclassical electron trajectories. The results are interpreted by the strong-field approximation (SFA) and the importance of the hole transfer during the tunneling process is emphasized. Finally, coherent population transfer between the inner and outer holes with attosecond pulse trains is discussed.