| 1. |
- Razdolski, I., et al.
(författare)
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Nonlocal nonlinear magneto-optical response of a magnetoplasmonic crystal
- 2013
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 88:7, s. 075436-
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Tidskriftsartikel (refereegranskat)abstract
- Surface plasma resonance (SPR) excitation in a Co-based two-dimensional magnetoplasmonic crystal was found to strongly enhance the second-harmonic generation (SHG) efficiency. Large changes in the phase shift between magnetic and nonmagnetic SHG contributions were observed in the transversal Kerr effect as a function of the incidence angle. The activation of a nonlocal quadrupole mechanism of the magnetic SHG due to the SPR excitation was found to lead to an unusual phase behavior in the vicinity of the resonance.
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| 2. |
- Iacocca, Ezio, 1986, et al.
(författare)
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Spin-current-mediated rapid magnon localisation and coalescence after ultrafast optical pumping of ferrimagnetic alloys
- 2019
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723 .- 2041-1723. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Sub-picosecond magnetisation manipulation via femtosecond optical pumping has attracted wide attention ever since its original discovery in 1996. However, the spatial evolution of the magnetisation is not yet well understood, in part due to the difficulty in experimentally probing such rapid dynamics. Here, we find evidence of a universal rapid magnetic order recovery in ferrimagnets with perpendicular magnetic anisotropy via nonlinear magnon processes. We identify magnon localisation and coalescence processes, whereby localised magnetic textures nucleate and subsequently interact and grow in accordance with a power law formalism. A hydrodynamic representation of the numerical simulations indicates that the appearance of noncollinear magnetisation via optical pumping establishes exchange-mediated spin currents with an equivalent 100% spin polarised charge current density of 10 7 A cm −2 . Such large spin currents precipitate rapid recovery of magnetic order after optical pumping. The magnon processes discussed here provide new insights for the stabilization of desired meta-stable states.
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| 3. |
- Mentink, J. H., et al.
(författare)
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Ultrafast Spin Dynamics in Multisublattice Magnets
- 2012
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 108:5, s. 057202-
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Tidskriftsartikel (refereegranskat)abstract
- We propose a general theoretical framework for ultrafast laser-induced spin dynamics in multisublattice magnets. We distinguish relaxation of relativistic and exchange origin and show that when the former dominates, nonequivalent sublattices have distinct dynamics despite their strong exchange coupling. Even more interesting, in the exchange dominated regime sublattices can show highly counterintuitive transitions between parallel and antiparallel alignment. This allows us to explain recent experiments with antiferromagnetically coupled sublattices, and predict that such transitions are possible with ferromagnetic coupling as well. In addition, we predict that exchange relaxation enhances the demagnetization speed of both sublattices only when they are antiferromagnetically coupled.
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| 4. |
- Wikberg, J. M., et al.
(författare)
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Evolving Magnetization Dynamics in Mn3-xGa
- 2015
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Ingår i: Springer Proceedings in Physics. - Cham : Springer International Publishing. - 0930-8989. ; 159, s. 23-25, s. 23-25
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Konferensbidrag (refereegranskat)abstract
- Magnetic materials with high magnetic coercivity (Hc), magnetic anisotropy (Ku) and low Gilbert damping (α) are of great importance for future spintronics devices. For instance, for spin-transfer-torque (STT) memory devices low α and high Ku are desired. Such a combination of material properties includes a built in contradiction since both Ku and α are dependent on the spin-orbit interaction (SO); a high Ku material is expected to have a high α. However, recent experimental investigations of Mn3-xGa, a material exhibiting high Curie temperature (Tc) > 700 K and (out-of-plane) perpendicular anisotropy, have shown that such a contradictorily low α and high Ku material exists.
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