RAMAN SPEKTROSKOPIE DISSERTATION

In addition to the development of a consistent and comprehensive description of Raman scattering, we derive a novel approach for the calculation of phonon frequencies and the screened electron-phonon coupling. Our new method goes beyond the limitations of the methods currently in use and will permit the computation of phonon-related quantities also in systems with strong correlation effects such as Kohn anomalies e. Doctoral thesis Discipline s: University of Luxembourg Library. Here we focus on the description of the phenomenon of magneto-phonon resonances and how it can be used to probe electronic excitation energies and to extract electron and phonon lifetimes. It can be applied also to strongly correlated systems, for which the currently used methods are not entirely satisfactory or insufficient.

Our new method goes beyond the limitations of the methods currently in use and will permit the computation of phonon-related quantities also in systems with strong correlation effects such as Kohn anomalies e. In this thesis, we aim to fill this gap and present a coherent theory of Raman scattering within the framework of many-body perturbation theory. Wirtz, Ludger Stampfer, Christoph President of the jury: This applies not only to graphene but also to other two-dimensional materials of current interest, such as MoTe2 and MoS2. Diese Vielseitigkeit macht ihre theoretische Beschreibung jedoch sehr herausfordernd, sodass bis heute kein allgemeiner ab initio Zugang existiert. Schmidt, Thomas Member of the jury:

Wirtz, Ludger Stampfer, Christoph President of the jury: Docteur en Physique; Doktor der Naturwissenschaften Number of pages: Doctoral thesis Discipline s: University of Luxembourg Library. All documents in ORBi lu are spekroskopie by a user license.

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Diese Vielseitigkeit macht ihre theoretische Beschreibung jedoch sehr herausfordernd, sodass bis heute kein allgemeiner ab initio Zugang existiert. This applies not only to spektroskolie but also to other two-dimensional materials of current interest, such as MoTe2 and MoS2.

Completed Theses

O pen R epository and Bi bliography. It can spetroskopie applied also to strongly correlated systems, for which the currently used methods are not entirely satisfactory or insufficient. Physics and Materials Science To cite this reference: As a first test case, we apply our theory to graphene, for which we use it to study the laser frequency and Fermi energy dependence of the Raman G-peak intensity.

raman spektroskopie dissertation

The latter has so far not been possible with state-of-the-art methods, which can only take into account one of the two effects. We develop a novel and general, correlation function-based approach for the calculation of Raman scattering rates that can potentially also be applied to ultra-fast Raman spectroscopy out of equilibrium.

raman spektroskopie dissertation

The flexibility of our approach also allows us to demonstrate that non-resonant processes and quantum mechanical interference effects play a significant role in Raman scattering. This versatility, however, makes its theoretical description very challenging and, up to now, no fully satisfactory and general way for the calculation of Raman spectra from first principles exists.

Completed Theses | 5th Institute of Physics | University of Stuttgart

In addition to the development of a consistent and disseryation description of Raman scattering, we derive a novel approach for the calculation of phonon frequencies and the screened electron-phonon coupling. Here we focus on the description of the phenomenon of magneto-phonon resonances and how it can be used to probe electronic excitation energies and to extract electron and phonon lifetimes.

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ORBi lu Detailled reference.

raman spektroskopie dissertation

Dies trifft auch auf andere zweidimensionale Materialien zu, wie z. Lastly, we present work on the application of magneto- Raman spectroscopy as cissertation probe for many-body effects in graphene.

In this thesis, we aim to fill this gap and present a coherent theory of Raman scattering within the framework of many-body perturbation theory. Schmidt, Thomas Member spektroskooie the jury: Besides these theoretical developments, we present concrete computational recipes for the calculation of Raman intensities that allow the inclusion of both excitonic effects and non-adiabatic effects of lattice vibrations.

Our new spektroskopid goes beyond the limitations of the methods currently in use and will permit the computation of phonon-related quantities also in systems with strong correlation effects such as Kohn anomalies e.