Sökning: "quantum mechanical calculations"

Visar resultat 1 - 5 av 83 avhandlingar innehållade orden quantum mechanical calculations.

1. 1. Quantum Mechanical Calculations of Thermoelectrical Polymers and Organic Molecules

   Författare :Amina Mirsakiyeva; Anna Delin; Clas Persson; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Quantum molecular dynamics; Car-Parrinello molecular dynamics; PEDOT; poly 3; 4-ethylenedioxythiophene ; Fysik; Physics;

   Sammanfattning : The subject of the present licentiate thesis is density functional theorybased electronic structure calculations of organic thermoelectric materials and novel organic molecules. We used the Car-Parrinello molecular dynamics method in order to investigate the electronic structure of “green energy” and “greenchemistry” compounds. LÄS MER

3. 2. Quantum Mechanical Studies of Electron Transport Processes Including Superconductivity

   Författare :Agris Klimkans; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quantum chemical calculations; ab initio; electronic;

   Sammanfattning : Processes of electron transfer, charge and spin localization, and electron pair transfer have been studied on the basis of the Marcus model and with the help of accurate quantum chemical calculations. A vibrational model, based on the corrections to the Born-Oppenheimerapproximation, which applies in the case of a vanishing barrier in the Marcus model, has been proposed. LÄS MER

4. 3. Quantum electronic transport in low-dimensional semiconductors

   Författare :Heiner Linke; Fasta tillståndets fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quantum transport; two-dimensional electron gas; contact-free characterisation; ballistic transport; mesoscopic; electron billiard; quantum dot; electron-electron interaction; non-linear; phase breaking; Halvledarfysik; Fysicumarkivet A:1997:Linke; non-symmetric conductio; Semiconductory physics; low-dimensional structures;

   Sammanfattning : Electronic transport is studied at low temperatures in two-dimensional electron gases (2DEGs) and in mesoscopic semiconductor microstructures. The method of microwave-detection of the Shubnikov-de Haas effect for the contact-free characterisation of transport properties of 2DEGs is explored using both magnetic-field modulation and light-induced carrier modulation. LÄS MER

5. 4. Electronic and Photonic Quantum Devices

   Författare :Erik Forsberg; KTH; []
   Nyckelord :electron waveguide devices; nanoelectronics; ballistic transport; electroabsorption modulators; Rabi oscillations; quantum measurements;

   Sammanfattning : In this thesis various subjects at the crossroads of quantummechanics and device physics are treated, spanning from afundamental study on quantum measurements to fabricationtechniques of controlling gates for nanoelectroniccomponents.Electron waveguide components, i.e. LÄS MER

7. 5. Combined Quantum Mechanical and Molecular Dynamics study of paramagnetic complexes : Towards an understanding of electronic spin relaxation

   Författare :Shehryar Khan; Michael Odelius; Jozef Kowalewski; Juha Vaara; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; molecular dynamics; quantum chemistry; zero-field splitting; kemisk fysik; Chemical Physics;

   Sammanfattning : The prime objectives of contrast agents in Magnetic Resonance Imaging (MRI) is to accelerate the relaxation rate of the solvent water protons in the surrounding tissue. Paramagnetic relaxation originates from dipole-dipole interactions between the nuclear spins and the fluctuating magnetic field induced by unpaired electrons. LÄS MER