Sökning: "quantum tunneling"

Visar resultat 1 - 5 av 103 avhandlingar innehållade orden quantum tunneling.

1. 1. Resonant Tunneling in Laterally Confined Quantum Structures

   Författare :Boel Gustafson; Fasta tillståndets fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; gravitation; relativity; quantum mechanics; classical mechanics; Mathematical and general theoretical physics; Fysik; Physics; High peak-to-valley ratio; Lateral confinement; Quantum dots; Resonant tunneling; Self-assembled quantum dots; Schottky depletion; Buried metal gate; Electron transport; Magnetic-field dependence; Energy level width; Tunneling transistors; Mode coupling; statistical physics; thermodynamics; Matematisk och allmän teoretisk fysik; klassisk mekanik; kvantmekanik; relativitet; statistisk fysik; termodynamik; Technological sciences; Teknik; Fysicumarkivet A:2001:Gustafson;

   Sammanfattning : In the thesis, three-dimensionally confined resonant tunneling structures were studied experimentally. Two approaches were used for obtaining quantum confinement: gate-defined lateral constriction of double barrier structures, and epitaxial growth of self-assembled quantum dots. LÄS MER

3. 2. Quantum and Ballistic Nanodevices

   Författare :Ivan Shorubalko; Fasta tillståndets fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; III-V semiconductors; low-dimensional structures; nanostructures; ballistic rectifiers; three-terminal ballistic junctions; quantum wires; planar quantum dots; logic gates; harmonic generation; InP; GaInAs; nanoelectronics; Fysik; Physics; nonlinear transport; electron transport; quantum nanodevices; ballistic nanodevices; Fysicumarkivet A:2003:Shorubalko;

   Sammanfattning : In this thesis, electron transport in quantum and ballistic devices was studied. The devices studied here were quantum wires, planar quantum dots, ballistic rectifiers, artificial functional materials, and three-terminal ballistic junctions. The possible application of such devices in the future nanoelectronics was also investigated. LÄS MER

4. 3. Tunneling Based Electronic Devices

   Författare :Erik Lind; Institutionen för elektro- och informationsteknik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; SiGe; Esaki Diodes; classical mechanics; quantum mechanics; relativity; termodynamik; relativitet; kvantmekanik; statistisk fysik; Matematisk och allmän teoretisk fysik; thermodynamics; gravitation; statistical physics; GaAs; Mathematical and general theoretical physics; Resonant Tunneling Permeable Base Transistors; Resonant Tunneling Diodes; klassisk mekanik; Fysicumarkivet A:2004:Lind;

   Sammanfattning : This thesis concerns different kinds of tunneling based devices all showing negative differential resistance. The thesis is divided in three parts, resonant tunneling transistors, Esaki diodes and coupled zero dimensional systems. LÄS MER

5. 4. Linear and Nonlinear Transport in Quantum Nanostructures

   Författare :Anneli Löfgren; Fasta tillståndets fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; magnetoconductance; mesoscopic; electron billiard; quantum dot; quantum ratchets; non-linear; symmetries; non-symmetric conduction; rectification; artificial material; Halvledarfysik; Fysicumarkivet A:2002:Löfgren; ballistic transport; quantum transport; 2DEG; Semiconductory physics; InP InGaAs; GaAs AlGaAs;

   Sammanfattning : In this thesis, electron transport in mesoscopic semiconductor nanostructures, in particular so-called electron billiards or quantum dots, is studied. The thesis can be divided into two areas: the linear response regime of transport, and the nonlinear response regime of transport. LÄS MER

7. 5. Theoretical modeling of scanning tunneling microscopy

   Författare :Alexander Gustafsson; Magnus Paulsson; Jorge Iribas Cerdá; Linnéuniversitetet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Scanning tunneling microscopy; Computational models; Quantum tunneling; Green s functions; Density functional theory; Condensed Matter Physics; Kondenserade materians fysik;

   Sammanfattning : The main body of this thesis describes how to calculate scanning tunneling microscopy (STM) images from first-principles methods. The theory is based on localized orbital density functional theory (DFT), whose limitations for large-vacuum STM models are resolved by propagating localized-basis wave functions close to the surface into the vacuum region in real space. LÄS MER