Sökning: "ThZ emission"

Visar resultat 1 - 5 av 9 avhandlingar innehållade orden 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. Study of MgB2 HEB mixers at THz frequencies

    Författare :Evgenii Novoselov; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; noise temperature; mixers; bandwidth; THz detectors; superconductors; bolometers; conversion gain; MgB2;

    Sammanfattning : The terahertz (THz) range is very attractive for astronomical observations. Spectroscopy and photometry of remote space objects in the THz range allows for a study of their chemical composition, because this range covers rotational lines from simple molecules and electron transition lines from atoms and ions. LÄS MER

  4. 3. Growth and Characterization of Strain-engineered Si/SiGe Heterostructures Prepared by Molecular Beam Epitaxy

    Författare :Ming Zhao; Wei-Xin Ni; Göran Hansson; Kang L. Wang; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Si SiGe; Strain engineering; Molecular beam epitaxy; THz; Quantum cascade; Strain relaxation; Materials science; Teknisk materialvetenskap;

    Sammanfattning : The strain introduced by lattice mismatch is a built-in characteristic in Si/SiGe heterostructures, which has significant influences on various material properties. Proper design and precise control of strain within Si/SiGe heterostructures, i.e. LÄS MER

  5. 4. 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

  7. 5. 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