Berlin 2014 – wissenschaftliches Programm

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A: Fachverband Atomphysik

A 3: Interaction with strong or short laser pulses I

A 3.3: Vortrag

Montag, 17. März 2014, 11:00–11:15, BEBEL E44/46

Laser field induced correlated tunneling of electrons — •Natalya Sheremetyeva, Mara Oßwald, and Alejandro Saenz — AG Moderne Optik, Institut für Physik, Humboldt-Universität zu Berlin, Newtonstraße 15, 12489 Berlin, Germany

Ionization is the central process that controls many phenomena occurring during the interaction of strong laser fields with matter. Often, only the ionization of valence electrons is considered. In reality, more electrons may be involved in the process and their dynamics is correlated. A theoretical description of this dynamics is complicated and in most cases some approximation has to be adopted.

Z. Walters and O. Smirnova proposed a semi-classical model, in which a weakly bound electron escapes from the nuclear potential via tunneling, generating an ’attosecond correlation pulse’. This pulse can excite a more strongly bound electron and can elevate it to the vacated energy level. Consequently, since the electrons are indistinguishable, it appears as if the more strongly bound electron has tunneled directly. Interestingly, it was found in [1] that this particular two-step process has a higher probability than direct tunnel ionization out of the deeper orbital.

We present a quantum-mechanical version of this model. Separate investigations of the influence of the external laser field and the electron interaction on the excitation probability of the more strongly bound electron allows us to search for specific effects due to tunneling. We find no evidence of a tunneling-specific ’attosecond correlation pulse’.

[1] Z. Walters and O. Smirnova, J. Phys. B, 43 (2010), p. 161002