Sökning: "Kondenserade materiens teori"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden Kondenserade materiens teori.

  1. 1. Numerical studies of spin chains and cold atoms in optical lattices

    Detta är en avhandling från Stockholm : KTH

    Författare :Sara Bergkvist Sylvan; Anders Rosengren; Richard Scalettar; [2007]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Teoretisk Fysik; Kondenserade materiens teori; NATURAL SCIENCES Physics Condensed matter physics; NATURVETENSKAP Fysik Kondenserade materiens fysik;

    Sammanfattning : An important, but also difficult, research field in condensed matter physics is that of strongly correlated systems. This thesis considers two topics in this field.The first topic is disorder and frustration in spin models. The introduction of disorder into quantum spin chains creates a complex problem. LÄS MER

  2. 2. Thermoelectric phenomena in low-dimensional semiconductor systems

    Detta är en avhandling från KFS AB

    Författare :Magnus Larsson; [2005]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; kvantmekanik; relativitet; gravitation; statistisk fysik; termodynamik; Semiconductory physics; Halvledarfysik; thermopower anomaly; thermoelectricity; thermionic couple; zone-folding; cool chip; ballistic; thermionic; Mathematical and general theoretical physics; Matematisk och allmän teoretisk fysik; thermodynamics; statistical physics; relativity; quantum mechanics; klassisk mekanik; classical mechanics;

    Sammanfattning : This thesis investigates thermoelectric effects, predominantly in low-dimensional semiconductors. Various novel phenomena are predicted, investigated and discussed. LÄS MER

  3. 3. Electrical Studies of Quantum Devices

    Detta är en avhandling från Solid State Physics, Lund University

    Författare :Sven-Bertil Carlsson; [1999]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Single electron transistor; Resonant tunneling diode; Quantized conductance; In situ measurements; Coulomb blockade Ratchet; Fysicumarkivet A:1999:Carlsson; Fysik; Physics;

    Sammanfattning : This thesis deals with electrical measurements on quantum devices. The thesis is divided into three major areas: electrical characterization, semiconductor devices, and metal devices. The electrical characterization part present problems and advantages with the measurement techniques used in the the thesis, .i. LÄS MER

  4. 4. Unifying first-principles and model approaches for strongly correlated materials : Interplay between long- and short-range correlations

    Detta är en avhandling från Lund University

    Författare :Fredrik Nilsson; [2019-01]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; first-principle methods; strongly correlated materials; GW approximation; cRPA; random-phase approximation; dynamical mean-field theory; GW DMFT; downfolding;

    Sammanfattning : In materials with open 3$d$ and 4$f$ shells the valence electrons are relatively localized around the atoms which leads to large electron-electron correlations. These, so called strongly correlated materials, exhibit many intriguing properties such as high $T_c$ superconductivity, colossal magneto-resistance and heavy fermion behaviour. LÄS MER

  5. 5. Studies of Material Properties using Ab Initio and Classical Molecular Dynamics

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Love Koči; Uppsala universitet.; [2008]
    Nyckelord :Atomic and molecular physics; molecular dynamics; phase transitions; melting; elasticity; equation of state; metals; rare gases; Atom- och molekylfysik;

    Sammanfattning : In this thesis, material properties have been examined under extreme conditions in computer-based calculations.The research on iron (Fe), nickel (Ni), and ferropericlase (Mg1-xFexO) are not only important for our understanding of the Earth, but also for an improved knowledge of these materials per se. LÄS MER