Sökning: "Stefano Bonetti"

Visar resultat 1 - 5 av 11 avhandlingar innehållade orden Stefano Bonetti.

  1. 1. Magnetization Dynamics in Nano-Contact Spin Torque Oscillators : Solitonic bullets and propagating spin waves

    Författare :Stefano Bonetti; Johan Åkerman; Thomas Silva; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; magnetism; spintronics; thin magnetic films; spin transfer torque; magnetization dynamics; spin waves; microwave oscillators; giant magneto-resistance; Magnetism; Magnetism;

    Sammanfattning : Magnetization dynamics in nano-contact spin torque oscillators (STOs) is investigated from an experimental and theoretical point of view. The fundamentals of magnetization dynamics due to spin transfer torque are given. A custom-made high frequency (up to 46 GHz) in large magnetic fields (up to 2. LÄS MER

  3. 2. Phase retrieval method for quantitative terahertz spectroscopy in reflection geometry

    Författare :Kasturie Jatkar; Stefano Bonetti; Magnus Berntsen; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Terahertz; reflection; THz spectroscopy; InSb; Physics; fysik;

    Sammanfattning : Terahertz time-domain spectroscopy (THz-TDS) is a reliable technique used for studying the complex optical properties of materials. Its frequency range makes it suitable for detecting low-energy collective excitations such as phonons, magnons, and plasmons. THz-TDS in transmission geometry has gained much attention over the years. LÄS MER

  4. 3. Experimental femtosecond-laser based investigations of model catalytic surface reactions

    Författare :Kess Marks; Henrik Öström; Stefano Bonetti; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; kemisk fysik; Chemical Physics;

    Sammanfattning : In order to be able to design novel catalytic processes more efficiently, detailed understanding of the catalyst-reactant interaction and the dynamics of the microscopic reaction steps is needed. The present thesis aims to contribute to the fundamental understanding of catalyst reactant systems by means of experiments using model systems in Ultra High Vacuum (UHV). LÄS MER

  5. 4. Spin dynamics in the terahertz regime

    Författare :Kumar Neeraj; Stefano Bonetti; Markus Kowalewski; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; fysik; Physics;

    Sammanfattning : It is known that the use of conventional optical lasers for the study of ultrafast magnetization dynamics imparts heat to the materials under study, which creates a highly non equilibrium state and masks the fundamental coupling processes leading to ultrafast demagnetization. In order to understand, control and manipulate the dynamics of spins in magnetic systems a new kind of radiation called terahertz (THz) is starting to be used in recent years. LÄS MER

  7. 5. Terahertz spin dynamics in metallic thin film ferromagnets

    Författare :Kumar Neeraj; Stefano Bonetti; Andreas Rydh; Michael Farle; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Terahertz; ultrafast magnetism; spin dynamics; spin nutation; magnetization switching; fysik; Physics;

    Sammanfattning : The past two decades have witnessed an increasing interest in understanding and controlling materials at the pico- and femtosecond time scales, the so-called ultrafast regime. Among the broad field of condensed matter physics, magnetism and magnetic materials have attracted much interest both from a fundamental and an applied perspective. LÄS MER