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Model of coherent electron dynamics in molecules
Šenk, Jan ; Kolorenč, Přemysl (advisor) ; Houfek, Karel (referee)
An ultrashort laser pulse photoionizing the molecule produces a superposition of a few cationic states. The coupling between the electrons and the nuclei has been predicted to cause fast decoherence. In this thesis, a two-dimensional model of coupled electron- nuclear dynamics in molecules is constructed. It is based on a harmonic potential in the nuclear degree of freedom and a double harmonic potential representing two centers that bind the electrons. The electronic potential's dependence on the nuclear configuration facilitates the coupling. Thanks to the simplicity of the model, it is numerically exactly solvable. We use the basis of its eigenstates to calculate the evolution of any initial state. Several quantities are used to measure decoherence and unravel the underlying mecha- nisms. Especially useful is the Wigner quasiprobability distribution. A few fundamental cases of the model are analyzed, and it is used to approximate the coherence dynamics in the normal modes of the H2O+ cation. 1
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Two-electron model of interatomic Coulombic decay
Šenk, Jan ; Kolorenč, Přemysl (advisor) ; Čížek, Martin (referee)
In this thesis we construct and examine a two-electron model of interatomic Coulom- bic decay (ICD). We base this model on an unperturbed hamiltonian with closed-form stationary solutions with a potential consisting of two finite square wells. The Coulombic interaction mediating the decay between the electrons is incorporated via time-dependent perturbation theory. We then examine the dependence of the decay widths on the inter- well distance, the depth of the right well and the energy of the ICD electron. The model correctly describes the inter-well dependence for high energy ICD electrons. 1
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