Search for dissertations about: "impurity levels"

Showing result 1 - 5 of 25 swedish dissertations containing the words impurity levels.

2. 1. Resonant states in modulation-doped heterostructures

   Author : Anders Blom; Matematisk fysik; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Mathematical and general theoretical physics; generation-recombination noise; THz laser; classical mechanics; relativity; quantum mechanics; statistisk fysik; gravitation; relativitet; kvantmekanik; klassisk mekanik; Matematisk och allmän teoretisk fysik; thermodynamics; termodynamik; statistical physics; donor energies; Si SiGe quantum well; central-cell effect; impurity absorption; Fysicumarkivet A:2003:Blom; Resonant states; impurity levels;

   Abstract : This thesis deals with the properties of donors placed inside or outside a heterostructure quantum well (QW). The focus of the investigation has been on the formation of resonant states, which are a hybridization of the discrete localized impurity levels and the continuous two-dimensional QW subbands. READ MORE

4. 2. Adiabatic Andreev Levels Under Irradiation - Coherent Dynamics and Dephasing

   Author : Niklas I:son Lundin; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES;

   Abstract : A study of the Andreev level current through a weakly voltage-biased single-mode superconducting quantum point contact under microwave irradiation is presented. The applied microwave field induces resonant transitions between the current carrying Andreev states localized to the contact region, which results in an increase of the dc subgap current by several orders of magnitude. READ MORE

5. 3. Collective Electron Dynamics in Mesoscopic Systems

   Author : Oleksandr Zazunov; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Andreev reflection; Josephson effect; qubit; composite fermions; Andreev levels; resonant tunneling; superconductivity; high-T c superconductors; quantum point contact; fractional quantum Hall effect;

   Abstract : This work is devoted to a theoretical investigation of collective electron dynamics in low dimensional materials and mesoscopic structures. A common feature of these studies is the focus on the properties of the low energy dynamics of conduction electrons. One class of studied materials is the high-Tc superconductor Nd2CuO4 and related compounds. READ MORE

6. 4. Electrical Properties of Gold-related Defect Complexes in Silicon

   Author : Einar Sveinbjörnsson; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; DLTS; gettering; Au in Si; lithium diffusion; Au-H complexes; Au-Li complexes; deep levels; phosphorus diffusion; hydrogen in silicon;

   Abstract : This thesis describes three extensive experiments concerning the properties of gold as an impurity atom in crystalline silicon. The first study is an investigation of the effect of phosphorus diffusion on the distribution of gold atoms within a silicon crystal. READ MORE

7. 5. Optical Properties of Low Dimensional Semiconductor Materials

   Author : Tiantian Han; Ying Fu; Per-Olof Holtz; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Semiconductor; Low dimensional; optics; Physics; Fysik;

   Abstract : This dissertation presents a serial study on optical properties of different semiconductor materials. Three main types of studies are addressed: The role of doping levels of N and Al atoms in the room-temperature photoluminescence (PL) of 4H-SiC films for optoelectronic applications; the use of a basic Monte Carlo method combined with probability calculations of the time-dependent Schroedinger equation to manifest multi-photon absorption and emission of II-VI compound quantum dots (QDs) for bioimaging; a theoretical quantum chemistry approach to study of structure and optical properties of InGaAsN and GaAs clusters for laser technology applications. READ MORE