Sökning: "Bloch waves"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden Bloch waves.

  1. 1. Effective properties of heterogeneous materials with applications in electromagnetics

    Författare :Christian Engström; Institutionen för elektro- och informationsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; homogenization; optics; acoustics; Electromagnetism; structural parameters; anisotropic material; inverse homogenization; Bloch waves; Maxwell s equations; Elektromagnetism; optik; akustik; Inverse bounds;

    Sammanfattning : Composite materials, i.e, mixtures of two or more materials, are commonly used in industry, because they often have outstanding properties in comparison with the original materials. In many cases the inhomogeneities are on a very fine scale, which makes it difficult to perform a full numerical simulation of the material. LÄS MER

  3. 2. Ferromagnetic resonance in films with growth induced anisotropy

    Författare :Sergey Manuilov; Alex Grishin; Boris Kalinikos; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ferromagnetic resonance; magnetic anisotropy; single-ion anisotropy model; ferrites; magnetic epitaxial films; magnetostatic waves; pulsed laser deposition; magnetic alloys; domains; domain wall transformations;

    Sammanfattning : This thesis discusses two different magnetic materials: epitaxial yttrium iron garnet (YIG) and heteromorphous CoFeB-SiO2 films. YIG films were grown by pulse laser deposition (PLD) techniques onto gadolinium gallium garnet (GGG) substrates of (111) and (001) crystal orientations. LÄS MER

  4. 3. A Play of Light and Spins: Excitation and Detection of Non-linear Magnetization Dynamics using Light

    Författare :Shreyas Muralidhar; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; spin waves; laser-induced magnetization dynamics; Brillouin light scattering; Spin Hall nano-oscillators; neuromorphic computing; Ising machines;

    Sammanfattning : The excitation and detection of magnetization dynamics play key roles in the field of spintronics and magnonics. In this thesis, we investigate a contactless method of exciting nonlinear magnetization dynamics using a femtosecond pulsed laser, and study the same with a Brillouin Light Scattering (BLS) microscope. LÄS MER

  5. 4. Dispersion Engineering : Negative Refraction and Designed Surface Plasmons in Periodic Structures

    Författare :Zhichao Ruan; Min Qiu; Henri Benisty; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; photonic crystal; dispersion property; negative refraction; surface plasmon polariton; designed surface plasmon; negative index material; layer-KKR method; finite-difference time-domain method; plane wave method; subwavelength imaging; open cavity; enhanced transmission; slowing light; Photonics; Fotonik;

    Sammanfattning : The dispersion property of periodic structures is a hot research topic in the last decade. By exploiting dispersion properties, one can manipulate the propagation of electromagnetic waves, and produce effects that do not exist in conventional materials. LÄS MER

  7. 5. Optical properties of active photonic materials

    Författare :Yong Zeng; Ying Fu; Philip Russell; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; nanophotonics; plasmonics; Theoretical chemistry; Teoretisk kemi;

    Sammanfattning : Because of the generation of polaritons, which are quasiparticles possessing the characteristics of both photonics and electronics, active photonic materials offer a possible solution to transfer electromagnetic energy below the diffraction limit and further increase the density of photonic integrated circuits. A theoretical investigation of these exciting materials is, therefore, very important for practical applications. LÄS MER