Sökning: "quantum wells"

Visar resultat 16 - 20 av 79 avhandlingar innehållade orden quantum wells.

  1. 16. Breaking the symmetry : spin splitting of hole subbands in strained quantum wells

    Författare :Oskar Mauritz; KTH; []
    Nyckelord :;

    Sammanfattning : Properties of the subband structure and related propertiesof quantum wells (QWs) are investigated, within the frameworkof the multi-band envelope function method. The subbands of aQW are replaced by discrete Landau levels when a magnetic fieldis applied perpendicular to the plane of the well. LÄS MER

  3. 17. Photoemission from Alkali Metal Overlayers: Quantum Wells, Photoelectron Interference and Atomic Structure Changes

    Författare :Dan Claesson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quantum well states; surface structure; alkali metals; angle resolved photoemission; surface electronic phenomena; thin films; collective excitations; electronic structure;

    Sammanfattning : Angle resolved photoelectron spectroscopy is used to investigate alkali metal overlayers on noble metal surfaces. The work deals with interference in photoemission, bulk electronic structure and adsorption induced changes of atomic structure, respectively. The relative importance of surface and bulk in photoemission has remained largely unexplored. LÄS MER

  4. 18. Effects of the Spin-Orbit Interaction on Transport and Optical Properties of III-V Semiconductor Quantum Wells

    Författare :Vladimir Froltsov; Matematisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; spin-orbit interaction; quantum well; III-V; Raman scattering; magnetoresistance; weak localization; spin distribution; magnetic field; Fysik; Physics; Fysicumarkivet A:2000:Froltsov; Halvledarfysik; Semiconductory physics; semiconductor;

    Sammanfattning : Effects of the intrinsic electron spin-orbit interaction on transport and optical properties of III-V semiconductor quantum wells have been studied theoretically. It is shown that due to crystal anisotropy of this interaction, the weak localization magnetoresistance in a magnetic field parallel to interfaces is very sensitive to the epitaxy growth direction and also to the orientation of the magnetic field with respect to the crystal axes. LÄS MER

  5. 19. Semiconductor Quantum Dots Studied by Time-Resolved Luminescence Techniques

    Författare :Jörg Siegert; KTH; []
    Nyckelord :quantum dots; semiconductors; photoluminescence; time-resolved;

    Sammanfattning : In this thesis time-resolved photoluminescence spectroscopyis presented as a powerful tool to study the carrier dynamicsin various self-assembled quantum dot (QD) structures, whichare potentially attractive for device applications. The experiments reveal the impact of proton irradiation onInGaAs QDs and comparable quantum wells. LÄS MER

  7. 20. Threshold and Temperature Characteristics of InGa(N)As-GaAs Multiple Quantum Well Lasers

    Författare :Göran Adolfsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; GaAs; Semiconductor lasers; molecular beam epitaxy; multiple quantum wells; characteristic temperature; temperature dependence; dilute nitrides; ambipolar diffusion; InGa N As;

    Sammanfattning : Semiconductor lasers emitting in the 1.3 μm regime are of interest for applications in access-networks like fiber-to-the-home and radio-over-fiber systems. Suchfiber optical networks are expected to replace the copper-based access-networks currently in use due to a continuously increasing demand on user bandwidth. LÄS MER