Sökning: "ultrafast dynamics"

Visar resultat 1 - 5 av 94 avhandlingar innehållade orden ultrafast dynamics.

  1. 1. Ultrafast Magnetization Dynamics : Element-selective studies of magnetic alloys using ultra short XUV pulses

    Författare :Rameez Saeed Malik; Olof Karis; Uwe Bovensiepen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; magnetization dynamics; magnetic alloys; HHG; ultrashort laser pulses; magneto-optical Kerr effect MOKE ; Gilbert damping; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : In this thesis, I investigate the ultrafast magnetization dynamics in 3d ferromagnets and their alloys with ultrashort laser pulses. The high harmonics generation (HHG) setup provides extreme-ultraviolet photons with energies 35-72 eV, which is the energy range where 3d metals have their M2,3 absorption edges. LÄS MER

  3. 2. Superdiffusive Spin Transport and Ultrafast Magnetization Dynamics : Femtosecond spin transport as the route to ultrafast spintronics

    Författare :Marco Battiato; Olle Eriksson; Hardy Gross; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ultrafast magnetisation dynamics; anomalous diffusion; femtosecond dynamics; magnetism; Materialvetenskap; Materials Science;

    Sammanfattning : The debate over the origin of the ultrafast demagnetization has been intensively active for the past 16 years. Several microscopic mechanisms have been proposed but none has managed so far to provide direct and incontrovertible evidences of their validity. LÄS MER

  4. 3. Theoretical perspectives on ultrafast and non-linear spectroscopy

    Författare :Emil Vinas Boström; Matematisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Non-linear optics; Ultrafast dynamics; Non-equilibrium Green s functions; Density functional theory; Multi-photon absorption; Second harmonic generation; Desorption dynamics; Auger decay; Charge-separation dynamics; Quantum Zeno effect; Fysicumarkivet A:2018:Vinas Boström;

    Sammanfattning : In this thesis we discuss a theoretical description of ultrafast and non-linear spectroscopy. Due to the high intensities and ultrashort pulse durations involved in such experiments, it is necessary to use an explicitly time-dependent formalism. LÄS MER

  5. 4. Magnetization dynamics of complex magnetic materials by atomistic spin dynamics simulations

    Författare :Raghuveer Chimata; Biplab Sanyal; Olle Eriksson; Koopmans Bert; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ultrafast remagnetization; ultrafast dynamics; magnetism; multiferroics; amorphous alloys; DFT; spinels magnetostriction; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : In recent years, there has been an intense interest in understanding the microscopic mechanism of laser induced ultrafast magnetization dynamics in picosecond time scales. Magnetization switching on such a time scale has potential to be a significant boost for the data storage industry. LÄS MER

  7. 5. Spin Current Generation in Magnetic Heterostructures and its Impact on Terahertz Emission : A Spin Dynamics Perspective

    Författare :Rahul Gupta; Peter Svedlindh; Olof Karis; Mathias Kläui; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; spin-orbit torque; spintronic terahertz emitter; spin dynamics; ultrafast spin dynamics; spin current; ferromagnetic resonance; Heusler; magnetic thin film; epitaxial film; Engineering Science with specialization in Solid State Physics; Teknisk fysik med inriktning mot fasta tillståndets fysik;

    Sammanfattning : The transfer of knowledge from one generation to another is key to the intellectualness of mankind. In the present information age, digital technology provides easy access to knowledge and information. LÄS MER