Search for dissertations about: "electronic excitations"

Showing result 21 - 25 of 82 swedish dissertations containing the words electronic excitations.

  2. 21. Electronic Structure Calculations: Materials with Weak and Strong Correlations

    Author : Krister Karlsson; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; photoemission spectroscopy; band structure calculations;

    Abstract : This thesis is devoted to studies of various electronic properties which can be extracted from photoemission spectroscopy. Both weakly and strongly correlated systems are discussed, ranging from free electron metal surfaces to strongly correlated copper oxide compounds. READ MORE

  4. 22. Adatoms, Quasiparticles & Photons : The Multifaceted World of Photoelectron Spectroscopy

    Author : Martin Månsson; Ulf Otto Karlsson; Oscar Tjernberg; Maria Carmen Asensio; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; angle-resolved photoelectron spectroscopy; electronic structure; electron dynamics; semiconductor surfaces; oxides; high-temperature superconductors; Material physics with surface physics; Materialfysik med ytfysik;

    Abstract : The experimental work presented in this thesis is based on a wide assortment of very advanced and highly sophisticated photoelectron spectroscopy (PES) techniques. The objective of the present study has been to reveal and understand the electronic structure and electron dynamics in a broad spectrum of materials, ranging from wide band gap oxides, via semiconductors along with metals, and finally high-temperature superconductors. READ MORE

  5. 23. Role of charge and spin fluctuations and their interplay in solids : A Green’s function approach

    Author : Tor Sjöstrand; Matematisk fysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Green’s function; correlations; collective excitations; screened interaction; electric polarization; orbital and spin magnetization; magnon-phonon interaction; Fierz ambiguity; time-dependent exchange-correlation potential;

    Abstract : Due to the large number of electrons, solid state physics boils down to many-body approximations in which only selected types of collective excitations are taken into account, guided by the emergent properties of the material under study. In this thesis, the collective excitations of primary interest are electronic charge and spin fluctuations(plasmons and magnons) and nuclear charge fluctuations (phonons). READ MORE

  6. 24. An X-ray Spectroscopic Study of Perovskites Oxides and Halides for Emerging Devices

    Author : Dibya Phuyal; Olof Karis; Manuel Bibes; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; perovskite oxides; halide perovskites; x-ray spectroscopy; electronic structure; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Abstract : This thesis investigates the electronic structures on several perovskite oxide and halide materials with a focus on light harvesting applications. The systematic study of the electronic properties of the transition metal oxides and post-transition metal halides is a key point if one is to understand their properties. READ MORE

  7. 25. Electronic Structure of intrinsic and doped Silicon Carbide and Silicon

    Author : Clas Persson; Risto Nieminen; Linköpings universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : Silicon (Si) is the most exploited material within the semiconductor device technology, mainly due to its relatively good electron and hole mobilities and the simplicity to fabricate and process the material. Silicon carbide (SiC) has, however, a wider band gap, a higher breakdown electric field strength, and a higher thermal conductivity, which makes SiC one of the most promising materials for high-power devices. READ MORE