Sökning: "Heterostructures"

Visar resultat 26 - 30 av 144 avhandlingar innehållade ordet Heterostructures.

  1. 26. Three-Dimensional Metal-Semiconductor Heterostructures for Device Applications

    Författare :Lars-Erik Wernersson; Institutionen för elektro- och informationsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Schottky contacts; space-charge spectroscopy; ballistic transport; Coulomb repulsion; electron interference; resonant tunnelling; lateral confinement; heterojunction permeable base transistor; resonant tunnelling diodes; Fysicumarkivet A:1998:Wernersson; Fysik; Physics; resonant tun; epitaxial overgrowth;

    Sammanfattning : Fabrication and characterisation of buried metal contacts in compound semiconductors are demonstrated. The contacts have been investigated due to their usage both as gates in transistors and as active or passive elements in novel devices. LÄS MER

  3. 27. Critical Phenomena and Exchange Coupling in Magnetic Heterostructures

    Författare :Martina Ahlberg; Gabriella Andersson; Björgvin Hjörvarsson; Steve Bramwell; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; phase transitions; critical behavior; 2D XY model; MOKE; magnetic thin films and superlattices; amorphous multilayers; magnetic proximity effects; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : The continuous phase transition in thin magnetic films and superlattices has been studied using the magneto-optical Kerr effect (MOKE) and polarized neutron scattering (PNR).  It has been shown that the critical behavior of amorphous thin films belonging to the 2D XY universality class can be described within the same theory as crystalline sample. LÄS MER

  4. 28. Growth and Characterisation of Non-linear Ferroelectric Heterostructures

    Författare :Khaled Khamchane; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : High dielectric constant or ferroelectric materials are needed for a range of devices, non-volatile ferroelectric computer memories, NVFRAMs, microwave devices utilising the non-linear polarisation as a function of electric field, or other microwave applications. High dielectric constant and low losses can be achieved in single crystals of ferroelectrics. LÄS MER

  5. 29. Graphene spin circuits and spin-orbit phenomena in van der Waals heterostructures with topological insulators

    Författare :Dmitrii Khokhriakov; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Graphene; Spin-charge conversion; Topological insulator; Spintronics; Proximity effect; Van der Waals heterostructures;

    Sammanfattning : Spintronics offers an alternative approach to conventional charge-based information processing by using the electron spin for next-generation non-volatile memory and logic technologies. To realize such technologies, it is necessary to develop spin-polarized current sources, spin interconnects, charge-to-spin conversion processes, and gate-tunable spintronic functionalities. LÄS MER

  7. 30. Electronic, Transport, and Optical Properties of Broken-Gap Heterostructures

    Författare :Karin Nilsson; Matematisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; relaxation; magnetic resonance; supraconductors; magnetic and optical properties; k.p calculations; Condensed matter:electronic structure; electrical; interband transport; electron-hole hybridization; spin polarization; spectroscopy; spektroskopi; Kondenserade materiens egenskaper:elektronstruktur; egenskaper elektriska; magnetiska och optiska ; supraledare; magnetisk resonans;

    Sammanfattning : This thesis examines the physical properties of broken-gap heterostructures using a multiband k.p model and self-consistent calculations. Broken-gap heterostructures, made from InAs, GaSb, and AlSb, are characterized by a special band alignment with an overlap between the InAs conduction band and the GaSb valence band. LÄS MER