Browsing by Author "Durin, G."

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  • Current-driven domain wall mobility in polycrystalline Permalloy nanowires: A numerical study
    (2014) Leliaert, Jonathan; Van de Wiele, B.; Vansteenkiste, A.; Laurson, L.; Durin, G.; Dupre, L.; Van Waeyenberge, B.
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
  • Ground state optimization and hysteretic demagnetization: the random-field Ising model
    (2005) Alava, M.J.; Basso, V.; Colaiori, F.; Dante, L.; Durin, G.; Magni, A.; Zapperi, S.
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    We compare the ground state of the random-field Ising model with Gaussian distributed random fields, with its nonequilibrium hysteretic counterpart, the demagnetized state. This is a low-energy state obtained by a sequence of slow magnetic-field oscillations with decreasing amplitude. The main concern is how optimized the demagnetized state is with respect to the best-possible ground state. Exact results for the energy in d=1 show that in a paramagnet, with finite spin-spin correlations, there is a significant difference in the energies if the disorder is not so strong that the states are trivially almost alike. We use numerical simulations to better characterize the difference between the ground state and the demagnetized state. For d⩾3, the random-field Ising model displays a disorder induced phase transition between a paramagnetic and a ferromagnetic state. The locations of the critical points R(DS)c and R(GS)c differ for the demagnetized state and ground state. We argue based on the numerics that in d=3 the scaling at the transition is the same in both states. This claim is corroborated by the exact solution of the model on the Bethe lattice, where the critical points are also different.
  • Influence of material defects on current-driven vortex domain wall mobility
    (2014) Leliaert, Jonathan; Van de Wiele, B.; Vansteenkiste, A.; Laurson, L.; Durin, G.; Dupre, L.; Van Waeyenberge, B.
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    Many future concepts for spintronic devices are based on the current-driven motion of magnetic domain walls through nanowires. Consequently a thorough understanding of the domain wall mobility is required. However, the magnitude of the nonadiabatic component of the spin-transfer torque driving the domain wall is still debated today as various experimental methods give rise to a large range of values for the degree of nonadiabaticity. Strikingly, experiments based on vortex domain wall motion in magnetic nanowires consistently result in lower values compared to other methods. Based on the micromagnetic simulations presented in this contribution we can attribute this discrepancy to the influence of distributed disorder which vastly affects the vortex domain wall mobility, but is most often not taken into account in the models adopted to extract the degree of nonadiabaticity.
  • A numerical approach to incorporate intrinsic material defects in micromagnetic simulations
    (2014) Leliaert, J.; Van de Wiele, B.; Vansteenkiste, A.; Laurson, L.; Durin, G.; Dupre, L.; Van Waeyenberge, B.
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
  • Thermal effects on transverse domain wall dynamics in magnetic nanostrips
    (2015) Leliaert, Jonathan; Van de Wiele, B.; Vandermeulen, J.; Coene, A.; Vansteenkiste, A.; Laurson, Lasse; Durin, G.; Van Waeyenberge, B.; Dupre, L.
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
  • Universality classes and crossover scaling of Barkhausen noise in thin films
    (2014) Laurson, L.; Durin, G.; Zapperi, S.
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä