@article {21898,
	title = {Wavelength-dependent nonsequential double ionization of magnesium by intense femtosecond laser pulses},
	journal = {PHYSICAL REVIEW A},
	volume = {100},
	year = {2019},
	abstract = {We report on a systematic investigation of wavelength scaling strong-field double ionization of Mg in intense laser fields. A significant decrease of nonsequential double ionization (NSDI) yield with increasing wavelength from 800{\textendash}2000 nm is observed. Our data is well reproduced by a three-dimensional Monte Carlo simulation considering recollision impact excitation cross section. We demonstrate that the NSDI of Mg mainly occurs via the first ionic excited state 
Mg
+
*
(
3
p
2
P
3
/
2
,
1
/
2
)
 pumped by returning electron impact process. The recollision impact direct ionization pathway plays a minor role here. The wavelength dependence of the NSDI ratio is due to the recollision energy-dependent excitation cross section as well as the electron wave packet diffusion effects, both sensitively depending on the wavelength. Our work represents a step towards strong-field double ionization experiments on Mg in the long wavelength limit and sheds light on the NSDI mechanism of alkaline-earth metal atoms.},
	url = {https://journals.aps.org/pra/abstract/10.1103/PhysRevA.100.033403}
}
