Sökning: "phonon instabilities"

Hittade 5 avhandlingar innehållade orden phonon instabilities.

  1. 1. Thermodynamical and Dynamical Instabilities from Ab initio Electronic-Structure Calculations

    Författare :Kristin Aslaug Persson; KTH; []
    Nyckelord :electronic structures; density functional theory; phonon instabilities; martensitic transformation; phase diagram;

    Sammanfattning : .... LÄS MER

  3. 2. Electronic and dynamical aspects of the stability of metallic structures

    Författare :Babak Sadigh; KTH; []
    Nyckelord :;

    Sammanfattning : The structural phase stability of several transition metalsystems have been studied, using first-principles electronicstructure calculations. Frozen phonon techniques have been usedto study the details of structural phase transformations e.g. LÄS MER

  4. 3. Diamond Devices Based on Valley Polarization

    Författare :Nattakarn Suntornwipat; Jan Isberg; Markus Gabrysch; Saman Majdi; Hitoshi Umezawa; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; CVD diamond; valleytronics; Negative Differential Mobility; NDM; electron polarization; Time-of-Flight; magnetotransport; carrier transport; drift velocity; valley-transistor; Transferred-Electron Oscillator; TEO; TED; Gunn diode;

    Sammanfattning : Diamond is a wide bandgap semiconductor with extreme properties such as high thermal conductivity, high breakdown field, high carrier mobilities and chemical inertness. These properties together with the possibility to synthesize high purity Single-Crystalline (SC) diamond by Chemical Vapor Deposition (CVD), make it a very interesting material and a candidate for use in power electronics and in hazardous environments. LÄS MER

  5. 4. Electron Transport and Charge Control in Epitaxial Graphene

    Författare :Michael Winters; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Graphene monolayers and bilayers have attracted research interest in both the physics and electronic materials communities owing to their unique band structures. In a pristine monolayer, carriers travel at the Fermi velocity v_f = 1e8 cm/s and exhibit linear dispersion. LÄS MER

  7. 5. Hydrodynamics of Binary Bose-Einstein Condensates and Hydro-elasticity of the Inner Crust of Neutron Stars

    Författare :Dmitry Kobyakov; Emil Lundh; Vitaly Bychkov; Mattias Marklund; Achim Schwenk; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Binary Bose-Einstein condensates in ultracold gases; hydrodynamics; quantum turbulence; neutron stars; the inner crust; nuclear astrophysics; fysik; Physics;

    Sammanfattning : In the present thesis, “Hydrodynamics of Binary Bose-Einstein Condensates and Hydro-elasticity of the Inner Crust of Neutron Stars”, the hydrodynamic effects, instabilities and superfluid turbulence in binary immiscible ultracold gases, and hydro-elastic macroscopic coupled modes and microscopic structure of the inner layers of the crust of neutron stars, are studied. The ultracold gas dynamics can be realized in the laboratory. LÄS MER