Bond-distance-dependent Auger decay of core-excited N2 using an ultrashort x-ray pump and continuous-wave IR-control scheme

Abstract

Resonant Auger spectra (RAS) of core-excited ${\mathrm{N}}_{2}$ are theoretically investigated by implementing an ultrashort x-ray pump and strong continuous-wave (CW) IR-control scheme. A femtosecond weak x-ray pump resonantly excites the nitrogen core-excited $1s\ensuremath{\rightarrow}{\ensuremath{\pi}}^{*}$ of the ${\mathrm{N}}_{2}$ molecule; a strong CW IR control induces dynamic Stark shift of the core-excited level. With the pulse duration of the ultrashort pump comparable to or even shorter than the period of the IR control, the time overlapping between the pump and control pulses reduces into a subcycle of the IR pulse; the efficient pumping process strongly depends on the dynamic Stark shift and the relative phase between the two pulses, resulting in a great manipulation of the core-excited wave-packet dynamics and the subsequent RAS. The results are numerically illustrated for the ${\mathrm{N}}_{2}$ molecule by a 2-fs x-ray pulse. The RAS also show a strong dependence on the bond-distance-dependent Auger decay probability.