Sökning: "THz-emission"

Hittade 4 avhandlingar innehållade ordet THz-emission.

1. 1. Superradiant THz wave emission from arrays of Josephson junctions

   Författare :Ievgenii Borodianskyi; Vladimir Krasnov; Yury Shukrinov; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Josephson junction; Superconductor; ThZ emission; high-Tc; Physics; fysik;

   Sammanfattning : High-power, continuous-wave, compact and tunable THz sources are needed for a large variety of applications. Development of power-efficient sources of electromagnetic radiation in the 0.1-10 THz range is a difficult technological problem, known as the “THz gap. LÄS MER

3. 2. Properties of small Bi2Sr2CaCu2O8 intrinsic Josephson junctions: confinement, flux-flow and resonant phenomena

   Författare :Sven-Olof Katterwe; Vladimir M. Krasnov; Alexey Ustinov; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; high-temperature superconductivity; intrinsic Josephson junctions; tunneling; fluxons; flux-flow oscillator; THz-emission; cavity resonances; polaritons; micro nano-fabrication; fysik; Physics;

   Sammanfattning : In this thesis, intrinsic Josephson junctions, naturally formed in the strongly anisotropic high-temperature superconductor Bi2Sr2CaCu2O8 (Bi-2212), are studied experimentally. For this purpose, small mesa structures are fabricated on the surface of single crystals using micro- and nano-fabrication tools, focused ion beam is used to reduce the area of the mesa-structures down to ≈ 1 × 1 μm2. LÄS MER

4. 3. High-frequency phenomena in small Bi2Sr2CaCu2O8+x intrinsic Josephson junctions

   Författare :Holger Motzkau; Vladimir M. Krasnov; Reinhold Kleiner; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; high-temperature superconductivity; Bi-2212; cuprates; intrinsic Josephson junctions; intrinsic tunneling; fluxons; flux-flow oscillator; THz-emission; cavity resonances; polaritons; electrical doping; micro nano-fabrication; fysik; Physics;

   Sammanfattning : In this thesis, the tunneling between individual atomic layers in structures of Bi2Sr2CaCu2O8+x based high-temperature superconductors are experimentally studied employing the intrinsic Josephson effect. A special attention is paid to the fabrication of small mesa structures using micro and nanofabrication techniques. LÄS MER

5. 4. Resonant states in modulation-doped heterostructures

   Författare :Anders Blom; Matematisk fysik; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER