Sökning: "spin current"

Visar resultat 16 - 20 av 114 avhandlingar innehållade orden spin current.

1. 16. Spin valves and spin-torque oscillators with perpendicualr magnetic anisotropy

   Författare :Seyed Majid Mohseni Armaki; Johan Åkerman; Andrew Kent; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Spin torque oscillator; perpendicular magnetic anisotropy; SRA - ICT; SRA - Informations- och kommunikationsteknik;

   Sammanfattning : Researches in spintronics, especially those remarkably classified in the current induced spin-transfer torque (STT) framework, circumvent challenges with different materials and geometries. Perpendicular magnetic anisotropy (PMA) materials are showing capability of holding promise to be employed in STT based spintronics elements, e.g. LÄS MER

3. 17. Engineering Magnetic Droplets in Nanocontact Spin-Torque Nano-Oscillators

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

   Sammanfattning : 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. LÄS MER

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

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

   Sammanfattning : 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. LÄS MER

5. 19. Theory of X-ray Absorption Spectra and Spin Transfer Torque

   Författare :Ola Wessely; Olle Eriksson; Lars Nordström; Eric Shirley; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; First principles calculations; X-ray absorption spectroscopy; Carbon nanotubes; Helical spin density waves; Hydrogen storage; Spin transfer torque; Fysik; Physics; Fysik;

   Sammanfattning : The subjects of the thesis are theoretical first principles calculations of X-ray absorption (XA) spectra and current induced spin transfer torque. XA spectra calculated from atomic multiplet theory and from band structure calculations, based on density functional theory for La0.7Sr0.3MnO3 have been compared to experiment. LÄS MER

7. 20. 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