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Aufsatz
Asymptotic model for shape resonance control of diatomics by intense non-resonant light
(2015)
We derive a universal model for atom pairs interacting with non-resonant light via the polarizability
anisotropy, based on the long range properties of the scattering. The corresponding dynamics can be
obtained using a nodal line technique to solve the asymptotic Schrödinger equation. It consists of
imposing physical boundary conditions at long range and vanishing the wavefunction at a position
separating the inner zone and the asymptotic region. We show that nodal lines which depend on the
intensity of the ...
Aufsatz
Femtosecond wavepacket interferometry using the rotational dynamics of a trapped cold molecular ion
(2015)
A Ramsey-type interferometer is suggested, employing a cold trapped ion and two time-delayed offresonant
femtosecond laser pulses. The laser light couples to the molecular polarization anisotropy,
inducing rotational wavepacket dynamics. An interferogram is obtained from the delay dependent
populations of the final field-free rotational states. Current experimental capabilities for cooling and
preparation of the initial state are found to yield an interferogram visibility of more than 80%. The
interferograms can ...
Dissertation
Fabrication of diamond nanostructures and investigation of the imbedded NV centers
(2015-02-24)
Diamant ist ein Material mit vielen außerordentlichen Eigenschaften, die ihn zu einem äußerst vielversprechenden Kandidaten für Anwendungen in Wissen-schaft und Technik machen. In den letzten Jahren wurde Diamant häufig als einzigartige Plattform für neue Anwendungen beispielsweise in der Quanteninformationstechnologie (QIT) oder in der Magnetometrie im Nanometermaßstab eingesetzt, wobei einer der wichtigsten lumineszierenden Gitterdefekte im Diamantgitter eingesetzt wird. Dabei handelt es sich um die sogenannten ...
Dissertation
Ab initio Molecular Dynamics Simulations of the Structural Response of Solids to Ultrashort Laser and XUV Pulses
(2015-04-10)
The theoretical model and underlying physics described in this thesis are about the interaction of femtosecond-laser and XUV pulses with solids. The key to understand the basics of such interaction is to study the structural response of the materials after laser interaction. Depending on the laser characteristics, laser-solid interaction can result in a wide range of structural responses such as solid-solid phase transitions, vacuum phonon squeezing, ultrafast melting, generation of coherent phonons, etc. During my ...
Dissertation
Magnetic interactions between transition metal impurities and clusters mediated by low-dimensional metallic hosts: A first principles theoretical investigation
(2015-03-31)
The magnetic properties and interactions between transition metal (TM) impurities and clusters in low-dimensional metallic hosts are studied using a first principles theoretical method. In the first part of this work, the effect of magnetic order in 3d-5d systems is addressed from the perspective of its influence on the enhancement of the magnetic anisotropy energy (MAE). In the second part, the possibility of using external electric fields (EFs) to control the magnetic properties and interactions between nanoparticles ...
Dissertation
Adsorption kinetic investigations of phthalocyanine derivatives self assembled monolayers (SAMs) on gold: Temperature influence on the SAM formation process and quality
(2015-08-12)
The ordered nano-structured surfaces, like self-assembled monolayers (SAMs) are of a great scientific interest, due to the low cost, simplicity, and versatility of this method. SAMs found numerous of applications in molecular electronics, biochemistry and optical devices. Phthalocyanine (Pc) complexes are of particular interest for the SAM preparation. These molecules exhibit fascinating physical properties and are chemically and thermally stable. Moreover their complex structure is advantageous for the fabrication ...
Aufsatz
Hybrid optimization schemes for quantum control
(Springer Open, 2015)
Optimal control theory is a powerful tool for solving control problems in quantum mechanics, ranging from the control of chemical reactions to the implementation of gates in a quantum computer. Gradient-based optimization methods are able to find high fidelity controls, but require considerable numerical effort and often yield highly complex solutions. We propose here to employ a two-stage optimization scheme to significantly speed up convergence and achieve simpler controls. The control is initially parametrized ...
Aufsatz
Spatio-temporal resolution studies on a highly compact ultrafast electron diffractometer
(2015)
Time-resolved diffraction with femtosecond electron pulses has become a promising technique to directly provide insights into photo induced primary dynamics at the atomic level in molecules and solids. Ultrashort pulse duration as well as extensive spatial coherence are desired, however, space charge effects complicate the bunching of multiple electrons in a single pulse.Weexperimentally investigate the interplay between spatial and temporal aspects of resolution limits in ultrafast electron diffraction (UED) on our ...