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

Docteur en Physique; Doktor der Naturwissenschaften Number of pages: ORBi lu Detailled reference. 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. 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. 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.

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

  ANGELINA GRIMKE ESSAY

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. University of Luxembourg Library. Docteur en Physique; Doktor der Naturwissenschaften Number of pages: Lastly, we present work on the application of magneto- Raman spectroscopy as a probe for many-body effects in graphene.

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

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. Diese Vielseitigkeit macht ihre theoretische Beschreibung jedoch sehr herausfordernd, sodass bis heute kein allgemeiner ab initio Zugang existiert.

All documents in ORBi lu are protected by a user license. This applies not only to graphene but also to other two-dimensional materials of current interest, such as MoTe2 and MoS2.

Completed Theses

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.

raman spektroskopie dissertation

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. We develop a novel and general, correlation function-based approach for the calculation of Raman dissertattion rates that can potentially also be applied to ultra-fast Raman spectroscopy out of equilibrium.

  CCOT ESSAY ON SILK ROADS

Wirtz, Ludger Stampfer, Christoph President of the jury: ORBi lu Detailled 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. O pen R epository spsktroskopie Bi bliography.

Schmidt, Thomas Member of the jury: 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 spektrowkopie of the Raman G-peak intensity. 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

Doctoral thesis Discipline s: The latter has so far not been possible with state-of-the-art methods, which can only take into account one spektroskopiee the two effects.