Sökning: "Femtosecond spectroscopy"

Visar resultat 16 - 20 av 62 avhandlingar innehållade orden Femtosecond spectroscopy.

1. 16. Optical Spectroscopy on Correlated Electron Materials

   Författare :Johan Bielecki; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; dynamics; optical spectroscopy; colossal magnetoresistance; magnetism; transition metal oxides; high temperature superconductivity;

   Sammanfattning : Strongly correlated materials poses a great challenge to our microscopic understanding of matter, mainly due to the inability of perturbative methods to predict the properties of such materials. This inability stems from strong correlations between electronic, lattice and spin degrees of freedom, leading to a variety of complex and exotic phenomena such as (unconventional) superconductivity, metal-insulator transitions, non-Fermi liquid behavior and colossal magnetoresistance. LÄS MER

3. 17. Conformational and Dynamical Aspects of Conjugated Polymers and Oligomers of Interest for Photoluminescence

   Författare :Mette Grage; Kemisk fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; femtosecond spectroscopy; conformations; anisotropy; excitation transfer; oligothiophene radical cations; MEH-PPV; Conjugated polymers; polythiophene; resonance Raman spectroscopy.; Chemistry; Kemi; Physics; Fysik;

   Sammanfattning : Transient absorption laser spectroscopy and resonance Raman spectrscopy have been used to study conjugated polymers and oligomers. To extract more information the measurements have been compared to computer simulations and calculations. LÄS MER

4. 18. Non-linear Spectroscopy of Conical Intersections with XUV and X-ray Photons

   Författare :Deependra Jadoun; Markus Kowalewski; Faris Gelmukhanov; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Conical Intersections; Non-linear Spectroscopy; Quantum Dynamics; Perturbation Theory; Ultrafast Spectroscopy; X-ray; XUV; Theoretical Physics; teoretisk fysik;

   Sammanfattning : Conical intersections (CIs) appear in a molecule due to the breakdown of the Born-Oppenheimer approximation when the energy difference between two or more electronic states decreases. CIs are known to play a crucial role in processes such as photosynthesis and vision in the human eye, and therefore it is important to probe the existence of such entities in molecules. LÄS MER

5. 19. Temporal Studies of Molecular Processes using Resonant Spectroscopy : Femtosecond experiments with synchrotron radiation and pulsed lasers

   Författare :Ingela Hjelte; Dennis Lindle; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Fysik; Physics; Fysik; fysik; Physics;

   Sammanfattning : The physical and chemical properties of matter are to a high degree determined by the electronic structure. One of the most powerful experimental techniques to study the electronic structure is electron spectroscopy. LÄS MER

7. 20. Metal-Organic Complexes at Surfaces

   Författare :Cristina Isvoranu; Synkrotronljusfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; x-ray absorption spectroscopy; x-ray photoelectron spectroscopy; bi-isonicotinic acid; oxalic acid; spin change; gas adsorption; metal-organic complex; iron phthalocyanine; scanning tunneling spectroscopy; resonant photoemission spectroscopy;

   Sammanfattning : The adsorption of different metal-organic complexes at surfaces was investigated by spectroscopic techniques (x-ray photoemission spectroscopy, x-ray absorption spectroscopy, resonant photoemission spectroscopy) and by scanning tunnelling microscopy. The investigation methods are able to provide atomic scale information on the studied systems, which moreover originates from the top-most atomic layers in a sample, meaning that they are surface sensitive techniques. LÄS MER