Sökning: "Quasiparticle."

Visar resultat 11 - 15 av 40 avhandlingar innehållade ordet Quasiparticle..

  1. 11. Cooling of a Suspended Nanowire by an ac Josephson current

    Författare :Milton Eduardo Peña-Aza; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nanoelectromechanical systems; nanowire; metallic carbon nanotubes; quantum ground state cooling of nanomechanical resonators; superconduting weak links; nanoelectromechanical Josephson junction;

    Sammanfattning : Nanoelectromechanical systems have been used for the exploration of the quantum limit of mechanical motion. There is hope that the quest for the quantum regime of these systems will shed light on fundamental questions in physics and lead to new quantum technologies. LÄS MER

  3. 12. Magnetic dipole excitations in even-even nuclei

    Författare :Charlotte Magnusson; Fysiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fysicumarkivet A:1991:Magnusson;

    Sammanfattning : The properties of K(pi) = 1+ states in deformed even-even rare-earth nuclei have been investigated within the Quasiparticle Random Phase Approximation (QRPA). The B(M1) spectrum and the differential cross section for electron scattering have been calculated and are seen to be consistent with the interpretation that the experimental 1+ states first considered to be a scissors mode, actually correspond to slightly collective states with the main proton components coming from positive parity proton states. LÄS MER

  4. 13. The Single Cooper Pair Box - a Quantum-Mechanical Electronic Circuit

    Författare :David Gunnarsson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quantum capacitance; quantum computing; single Cooper-pair box; SET; radio-frequency single-electron-transistor; macroscopic quantum coherence; Qubit;

    Sammanfattning : In this thesis the single Cooper pair box (SCB) is investigated with a radio frequency single electron transistor (RF-SET). The RF-SET is used as an electrometer to detect the charge of the SCB. The SCB can be regarded as a quantum two-level system and could therefore be a possible qubit. LÄS MER

  5. 14. Quantum effects in nanoscale Josephson junction circuits

    Författare :Silvia Corlevi; David B. Haviland; Jukka Pekola; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Josephson junctions; Josephson junction arrays; electromagnetic environment; Cooper pair transistor; parity effects; Physics; Fysik;

    Sammanfattning : This thesis presents the results of an experimental study on single-charge effects in nanoscale Josephson junctions and Cooper pair transistors (CPTs). In nanoscale Josephson junctions the charging energy EC becomes significant at sub-Kelvin temperatures and single-charge effects, such as the Coulomb blockade of Cooper pair tunneling, influence the transport properties. LÄS MER

  7. 15. Exciton-plasmon interactions in metal-semiconductor nanostructures

    Författare :Staffan Hellström; Ying Fu; Mikael Käll; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; plasmons; excitons; quantum dots; nanoparticles; FDTD; surface plasmon polaritons; QDIP; quantum dot infrared photodetector; polaritons;

    Sammanfattning : Semiconductor quantum dots and metal nanoparticles feature very strong light-matter interactions, which has led to their use in many photonic applications such as photodetectors, biosensors, components for telecommunications etc.Under illumination both structures exhibit collective electron-photon resonances, described in the frameworks of quasiparticles as exciton-polaritons for semiconductors and surface plasmon-polaritons for metals. LÄS MER