Sökning: "green-function technique"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden green-function technique.

1. 1. Non-Orthogonality and Electron Correlations in Nanotransport : Spin- and Time-Dependent Currents

   Författare :Jonas Fransson; Antti-Pekka Jauho; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; non-orthogonality; non-equilibrium; transport; nanosystem; quantum dot; spin-dependent; renormalization; Green function; diagram technique; many-body states; Hubbard operator; electron correlations; time-dependent; Fysik; icke-ortogonal; icke-jämvikt; transport; nanosystem; kvantprick; spinberoende; renormering; Green-funktion; diagramteknik; mångkropparstillstånd; Hubbadoperator; elektronkorrelationer; tidsberoende; Physics; Fysik; Fysik; Physics;

   Sammanfattning : The concept of the transfer Hamiltonian formalism has been reconsidered and generalized to include the non-orthogonality between the electron states in an interacting region, e.g. quantum dot (QD), and the states in the conduction bands in the attached contacts. LÄS MER

3. 2. Wave Propagation in Structural Elements - Direct and Inverse Problems in the Time Domain

   Författare :Peter Folkow; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; integro-differential equations; non-uniform beams; wave splitting; wave propagator; finite difference; Timoshenko beam; imbedding; Mindlin plate; inverse problem; viscoelastic damping; nonlinear rod; transient wave propagation; Green function;

   Sammanfattning : The subject of this thesis is direct and inverse wave propagation problems in structural elements. The considered structures are beams, plates and rods. The models for the beams and the plates are based on linear theory, while the rods are assumed to be nonlinear. The greater part of the work concerns the Timoshenko beam. LÄS MER

4. 3. Collective Excitation Dynamics in Molecular Aggregates

   Författare :Mats Dahlbom; Kemisk fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemistry; Kemi; Fysik; Physics; computational methods; photosynthesis; femtosecond spectroscopy; Exciton; Polaron;

   Sammanfattning : The aim of this thesis is to study collective excitation dynamics in molecular aggregates. Half of the work presented here is method development and the remainder is application of these methods to several di.erent molecular aggregates. LÄS MER

5. 4. Structural Information Content of the Optical Field

   Författare :Per Martinsson; Ari Friberg; Karl-Heinz Brenner; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Photonics; Fotonik;

   Sammanfattning :  The communication modes are a mathematical technique for the description of structural information in optical fields. These modes are orthogonal, optimally  connected functions characteristic of the optical system. Mathematically they are obtained by the singular value decomposition (SVD) of the operator that represents the field propagation. LÄS MER

7. 5. Dissipative Processes in Superconducting Diffusive Tunnel Junctions

   Författare :Andrey Vasenko; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Josephson effect; Andreev bound states; nonequilibrium superconductivity; superconducting junctions; transport processes; tunneling; diffusive superconductors;

   Sammanfattning : A central subject of this thesis is the dissipative current transport in superconducting tunnel junctions with diffusive electrodes. Tunnel current transport in superconducting junctions is a classical topic of interest and research. LÄS MER