Attosecond Transient Absorption Spectroscopy of doubly-excited states in\n helium

2012/11/12 by Luca Argenti, Argenti, Luca, Christian Ott +5
Physics and Astronomy · Engineering · #Laser-Matter Interactions and Applications #Spectroscopy and Quantum Chemical Studies #Laser Design and Applications

paper · pdf · doi:10.48550/arxiv.1211.2566

Abstract

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

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