RAMAN SPEKTROSKOPIE DISSERTATION

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. It can be applied also to strongly correlated systems, for which the currently used methods are not entirely satisfactory or insufficient. 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. 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. 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.

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. Doctoral thesis Discipline s: Physics and Materials Science To cite this reference: 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. 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.

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.

  DISSERTATION BINDING HIGHBURY

raman spektroskopie dissertation

ORBi lu Detailled reference. This applies not only to graphene but also to other two-dimensional materials of current interest, such as MoTe2 and MoS2. University of Luxembourg Library.

Completed Theses

O pen R epository and Bi bliography. 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.

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. Doctoral thesis Discipline s: Physics and Materials Science To cite this reference: Diese Vielseitigkeit macht ihre theoretische Beschreibung jedoch sehr herausfordernd, sodass bis heute kein allgemeiner ab initio Disertation existiert. The latter has so far not been possible with state-of-the-art methods, which can only dissegtation into account one of the two effects.

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.

raman spektroskopie dissertation

Schmidt, Thomas Member of the jury: Dies trifft auch auf andere zweidimensionale Materialien zu, wie z. 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.

  FWPARKER 6TH HOMEWORK

It can be applied also to strongly correlated systems, for which the currently used methods are not entirely satisfactory or insufficient. Lastly, we present work on the application of magneto- Raman spectroscopy as a probe for many-body effects in graphene. Docteur en Physique; Doktor der Naturwissenschaften Number of pages: 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.

Wirtz, Ludger Stampfer, Christoph President of the jury: 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

All documents in ORBi lu are protected by a user license. 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.

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.