Sökning: "phonon spectroscopy"

Visar resultat 1 - 5 av 44 avhandlingar innehållade orden phonon spectroscopy.

  1. 1. Frequency comb Brillouin microscopy

    Författare :Felipe Ademir Alemán Hérnandez; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Brillouin light scattering; optics; spinwave spectroscopy; phonon spectroscopy; microscopy; Fabry-Perot interferometer; Frequency comb;

    Sammanfattning : Brillouin light scattering (BLS), an almost a century-old technique, has evolved into a powerful and versatile method to study acoustic and magnetic phenomena down to the nanometer size scale. Presently, BLS can be applied in fields as diverse as acoustics, spintronics, geosciences, and biophysics. LÄS MER

  3. 2. Electron-Phonon Interactions in Transition Metal Oxides Studied by Resonance Raman Scattering

    Författare :Jakob Andreasson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Franck-Condon; Fr ohlich interaction; higher order scattering; perovskite; transition metal oxide; two-phonon; oxygen breathing mode; Raman spectroscopy;

    Sammanfattning : In this thesis, studies of strong electron-phonon interactions in a number of transition metal oxides are presented. Two different electron-phonon interaction mechanisms are identified; Franck-Condon scattering and infrared active longitudinal optical (IR LO) two-phonon activation. LÄS MER

  4. 3. Coherent Multidimensional Spectroscopy: Development of Efficient Data Acquisition and Analyses of Quantum Dot 2D Spectra

    Författare :Zhengjun Wang; NanoLund: Centre for Nanoscience; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Coherent Multidimensional Spectroscopy; quantum beating; quantum coherence; 2D electronic spectroscopy; 2D fluorescence spectroscopy; Compressed Sensing theory; CdSe QDs; LH2;

    Sammanfattning : Coherent multidimensional spectroscopy (CMDS) is the most complete nonlinear optical technique based on the interaction of multiple short laser pulses with matter. It has grown to play a significant role in studies of optoelectronic materials and pigment protein complexes. LÄS MER

  5. 4. 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

  7. 5. Modeling Vibrational Electron Energy Loss Spectroscopy with the Frequency-Resolved Frozen Phonon Multislice Method

    Författare :Paul Michel Zeiger; Jan Rusz; Rebecca Nicholls; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Electron Energy Loss Spectroscopy; Phonons; Scanning Transmission Electron Microscopy; Frozen Phonon Multislice; Molecular Dynamics; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : Aberration correctors, improved monochromators, and better detectors have enabled exciting research with nanometer- and Ångstrom-scale resolution in the Scanning Transmission Electron Microscope (STEM). However the interaction of high-energy electrons with the many-body system of the sample is quite complex and hinders interpretation of experiments. LÄS MER