Attosecond Electron Wave-Packet Interference Observed by Transient Absorption

Abstract

We perform attosecond time-resolved transient absorption spectroscopy around the first ionization threshold of helium and observe rapid oscillations of the absorption of the individual harmonics as a function of time delay with respect to a superimposed, moderately strong infrared laser field. The phase relation between the absorption modulation of individual harmonics gives direct evidence for the interference of transiently bound electronic wave packets as the mechanism behind the absorption modulation.

Time-resolved spectroscopy of doubly-excited states in helium

“…Wave packets formed by single electrons on attosecond time scales have recently been observed in helium [1,2]. For the case of two electrons, dynamical wave packets have thus far only been predicted theoretically [3].…”

Phase-resolved two-dimensional spectroscopy of electronic wave packets by laser-induced XUV free induction decay

“…This technique provides rich information about the interplay between the laser field and the Coulombic potential on the excited electron dynamics. Its background-free nature enables us to use a large range of gas pressures and to reveal the influence of collisions in the relaxation process.Transient Absorption Spectroscopy (TAS) in the extreme ultraviolet (XUV) range is a powerful technique for ultrafast dynamical studies, from the gas phase [1][2][3] to the solid state [4,5]. The recent progress of attosecond science has made the extension of TAS to the attosecond regime (ATAS) a reality.…”

“…Transient Absorption Spectroscopy (TAS) in the extreme ultraviolet (XUV) range is a powerful technique for ultrafast dynamical studies, from the gas phase [1][2][3] to the solid state [4,5]. The recent progress of attosecond science has made the extension of TAS to the attosecond regime (ATAS) a reality.…”

Spatial and temporal control of populations, branching ratios, and electronic coherences in LiH by a single one-cycle infrared pulse

“…Several experimental schemes rely on the CEP phase value of a CEP stable few cycle pulse [17] for tailoring the electric field profile of the pump pulse and controlling electron localization and dissociation. [8,[18][19][20][21][22][23][24][25] Photoinduced coherent electronic dynamics can also be probed using high harmonic generation [13,[26][27][28], transient absorption spectroscopy [29][30][31], time-resolved molecular-frame photoelectron-angular-distribution [32] and attoclock measurements [33,34].…”