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arXiv · 1211.2566

Attosecond Transient Absorption Spectroscopy of doubly-excited states in helium

Luca Argenti·Christian Ott·Thomas Pfeifer·Fernando Martín
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Abstract

Strong-field manipulation of autoionizing states is a crucial aspect of electronic quantum control. Recent measurements of the attosecond transient absorption spectrum of helium dressed by a few-cycle visible pulse [Ott et al., arXiv:1205.0519[physics.atom-ph] ] provide evidence of novel ultrafast resonant phenomena, namely, two-photon Rabi oscillations between doubly-excited states and the inversion of Fano profiles. Here we present the results of accurate \emph{ab-initio} calculations that agree with these observations and in addition predict that (i) inversion of Fano profiles is actually periodic in the coupling laser intensity and (ii) the supposedly dark $2p^2$ {$^1$S} state also appears in the spectrum. Closer inspection of the experimental data confirms the latter prediction.

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Luca Argenti, Christian Ott, Thomas Pfeifer, Fernando Martín. 2012-11-12. Attosecond Transient Absorption Spectroscopy of doubly-excited states in helium. https://arxiv.org/abs/1211.2566

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