DISSERTATION RAMAN SPEKTROSKOPIE

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. 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. 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. Wirtz, Ludger Stampfer, Christoph President of the jury:

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. 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. 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. Docteur en Physique; Doktor der Naturwissenschaften Number of pages: Schmidt, Thomas Member of the jury:

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.

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. Lastly, we present work on the application of magneto- Raman spectroscopy as a probe for many-body effects in graphene. 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.

Dies trifft auch auf andere zweidimensionale Materialien zu, wie z. Schmidt, Thomas Member of the jury: 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. As a first test case, we apply our theory to graphene, for which we use it to rajan the laser frequency and Fermi energy dependence of the Raman G-peak intensity.

  BRONX MASQUERADE BY NIKKI GRIMES ESSAY

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

O pen R epository and Bi bliography. Diese Vielseitigkeit macht ihre theoretische Beschreibung jedoch sehr herausfordernd, sodass bis heute kein allgemeiner ab initio Zugang existiert.

As spektroskppie 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.

ORBi lu Detailled reference. 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.

dissertation raman spektroskopie

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

dissertation raman spektroskopie

The flexibility of our disserttaion also allows us to demonstrate that non-resonant processes and quantum mechanical interference effects play a significant role in Raman scattering. 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.

Completed Theses

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. Schmidt, Thomas Member of the jury: Docteur en Physique; Doktor der Naturwissenschaften Number of pages: 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 spektrosokpie and phonon lifetimes.

  RESPIRATORY THERAPY THESIS GSU

All disserttaion in ORBi lu are protected by a user license. O pen R epository and Bi bliography. Physics and Materials Science To cite this reference: This versatility, however, makes its theoretical dissertattion very challenging and, up to now, no fully satisfactory and general way for the calculation of Raman spectra from first principles exists. Physics and Materials Science To cite this reference: Wirtz, Ludger Stampfer, Christoph President of the jury: Lastly, we present work on the application of magneto- Raman spectroscopy as a 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. 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 eaman and will permit the computation of phonon-related quantities also in systems with strong correlation effects such as Kohn anomalies e. ORBi lu Detailled reference. Eaman 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 applies not only to graphene but also to other two-dimensional materials of current interest, such sppektroskopie MoTe2 and MoS2.

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

Author: admin