Search for dissertations about: "Johan Åkerman"

Showing result 1 - 5 of 13 swedish dissertations containing the words Johan Åkerman.

  1. 1. Determining and Optimizing the Current and Magnetic Field Dependence of Spin-Torque and Spin Hall Nano-Oscillators : Toward Next-Generation Nanoelectronic Devices and Systems

    Author : Seyed Amir Hossein Banuazizi; Johan Åkerman; Erik Wahlström; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nanoelectronics; spintronics; nanomagnetism; ferromagnetic materials; microwave oscillators; magnetization dynamics; spin waves; giant magneto-resistance; spin Hall effect; spin-torque nano-oscillators; spin Hall nano-oscillators; numerical modeling; electrical characterization; microwave characterization; magnetic force microscopy.; Physics; Fysik; Materials Science and Engineering; Teknisk materialvetenskap; Informations- och kommunikationsteknik; Information and Communication Technology; Electrical Engineering; Elektro- och systemteknik;

    Abstract : Spin-torque and spin Hall nano-oscillators are nanoscale devices (about 100 nm) capable of producing tunable broadband high-frequency microwave signals ranging from 0.1 GHz to over 65 GHz that several research groups trying to reach up to 200 - 300 GHz. READ MORE

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

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

    Abstract : 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. READ MORE

  3. 3. Microwave Frequency Stability and Spin Wave Mode Structure in Nano-Contact Spin Torque Oscillators

    Author : Anders Eklund; B. Gunnar Malm; Johan Åkerman; Mikael Östling; Erik Wahlström; KTH; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; NATURVETENSKAP; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; ENGINEERING AND TECHNOLOGY; spintronics; microwave oscillators; magnetization dynamics; spin waves; phase noise; device modelling; electrical characterization; X-ray microscopy; STXM; XMCD; Physics; Fysik; Electrical Engineering; Elektro- och systemteknik;

    Abstract : The nano-contact spin torque oscillator (NC-STO) is an emerging device for highly tunable microwave frequency generation in the range from 0.1 GHz to above 65 GHz with an on-chip footprint on the scale of a few μm. READ MORE

  4. 4. Titled and graded anisotropy FePt and FePtCu thin films for the application of hard disk drive and spin torque oscillators

    Author : Yeyu Fang; Johan Åkerman; Anna Delin; KTH; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; Physics; Fysik;

    Abstract :  The FePt and FePtCu thin films with graded anisotropy and titled anisotropy are utilized to solve both the magnetic recording ‘‘trilemma’’ of the hard disk drives (HDDs) and the large field operation problem of spin torque oscillators (STOs). We have successfully realized the FePtCu thin films with graded anisotropy. READ MORE

  5. 5. Engineering Magnetic Droplets in Nanocontact Spin-Torque Nano-Oscillators

    Author : Sheng Jiang; Johan Åkerman; Dario Arena; KTH; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Magnetic Droplet; Magnetic Tunnel Junction; Perpendicular Magnetic Anisotropy; Spin-torque Nano-Oscillators; Spin-Valve.; Physics; Fysik;

    Abstract : Spin-torque nano-oscillators (STNOs) are nanoscale spintronic devices capable of generating highly tunable broadband microwave signals. In this thesis, I study nanocontact (NC)-based STNOs using strong perpendicular magnetic anisotropy(PMA) free layers, where a novel magnetic soliton—a magnetic droplet—exists. READ MORE