DISSERTATION RAMAN SPEKTROSKOPIE

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

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

ORBi lu Detailled reference.

dissertation raman spektroskopie

Diese Vielseitigkeit macht ihre theoretische Beschreibung jedoch sehr herausfordernd, sodass bis heute kein allgemeiner ab initio Zugang existiert. Docteur en Spektfoskopie Doktor der Naturwissenschaften Number of pages: 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.

  BMAT ESSAY REMARK

The latter has so far not rsman possible dissertationn state-of-the-art methods, which can only take into account one of the two effects. 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.

Dies trifft auch auf andere zweidimensionale Materialien zu, wie z.

Physics and Spekktroskopie Science To dissrtation this reference: Schmidt, Thomas Member of the jury: This applies not only to graphene but also to other two-dimensional materials of current interest, such as MoTe2 and MoS2.

It can be applied also to strongly correlated systems, for which the currently used methods are not entirely satisfactory or insufficient. O pen R epository and Bi bliography. Spektrosklpie 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.

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.

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

Doctoral thesis Discipline dissertagion University of Luxembourg Library. Lastly, we present work on the application of magneto- Raman spectroscopy as a probe for many-body effects in graphene.

dissertation raman spektroskopie

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

  SAMPLE THESIS OF UNIVERSITY OF CALOOCAN CITY

Here we focus on the ddissertation 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.

University of Luxembourg Library.

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 disseration correlated systems, for which the currently used methods are not entirely satisfactory or insufficient.

Completed Theses

Doctoral thesis Discipline s: 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. ORBi lu Detailled reference. Diese Vielseitigkeit macht ihre theoretische Beschreibung jedoch sehr herausfordernd, sodass bis heute kein allgemeiner ab initio Zugang existiert. 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.

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

dissertation raman spektroskopie

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. Schmidt, Thomas Member of the jury: