Domain Wall Dynamics

Domain Wall Dynamics

m000045

Description of the project

The study of domain wall dynamics in ferromagnets encompasses several core ideas of modern theoretical physics, including topology and non-equilibrium statistical physics. This research project focuses on theoretical and numerical studies of dynamics of domain walls in various low-dimensional ferromagnetic structures such as thin films, nanowires and -strips. The key issues to be addressed are the effects of structural disorder and thermal fluctuations on the domain wall dynamics, driven by either applied magnetic fields or spin-polarized electric currents. The study relates in particular to fundamental theoretical questions in modern statistical physics of elastic interfaces in random media, and has also important practical implications for the operation of next generation memory and logic devices based on domain walls. The project is pursued within the COMP Centre of Excellence in Computational Nanoscience (Aalto University, Dept. of Applied Physics), in collaboration both locally within Aalto University and with several partners across Europe, also via a European Commission Initial Training Network “WALL” on domain walls.

People

Dr. Lasse Laurson, Project leader, Academy Research Fellow (lasse.laurson (at) aalto.fi)

Touko Herranen, Doctoral Student (touko.herranen (at) aalto.fi)

Ilari Rissanen, Doctoral Student (ilari.rissanen (at) aalto.fi)

Former members:

Dr. Virginia Estevez Nuño

Publications

1. T. Herranen and L. Laurson, Bloch line dynamics within moving domain walls in 3D ferromagnets, submitted (2017), arXiv preprint available here.

2. V. Estevez and L. Laurson, Fast vortex wall motion in wide Permalloy strips due to double switching of the vortex core, Phys. Rev. B 96, 064420 (2017). Part of a figure selected for PRB Kaleidoscope.

3. S. Janicevic, L. Laurson, K. J. Måløy, S. Santucci, and M. J. Alava, Interevent Correlations from Avalanches Hiding Below the Detection Threshold, Phys. Rev. Lett. 117, 230601 (2016). Also featured in APS Physics, and by IOP Physics World “Flash Physics”.

4. I. Rissanen and L. Laurson, Coarsening dynamics of topological defects in thin Permalloy films,  Phys. Rev. B 94, 144428 (2016).

5. J. Leliaert, B. Van de Wiele, A. Vansteenkiste, L. Laurson, G. Durin, L. Dupre, and B. Van Waeyenberge, Creep turns linear in narrow ferromagnetic nanostrips, Sci. Rep. 6, 20472 (2016).

6. V. Estevez and L. Laurson, Magnetic domain-wall dynamics in wide Permalloy strips, Phys. Rev. B 93, 064403 (2016). Part of a figure selected for PRB Kaleidoscope.

7. T. Herranen and L. Laurson, Domain walls within domain walls in wide ferromagnetic strips, Phys. Rev. B 92, 100405(R) (2015).

8. V. Estevez and L. Laurson, Head-to-head domain wall structures in wide Permalloy strips,  Phys. Rev. B 91, 054407 (2015).

9. J. Leliaert, B. Van de Wiele, J. Vandermeulen, A. Coene, A. Vansteenkiste, L. Laurson, G. Durin, B. Van Waeyenberge, and L. Dupre, Thermal effects on transverse domain wall dynamics in magnetic nanowires, Appl. Phys. Lett. 106, 202401 (2015).

10. L. Laurson, G. Durin, and S. Zapperi, Universality classes and crossover scaling of Barkhausen noise in thin films, Phys. Rev. B 89, 104402 (2014). Fig. 1 selected for PRB Kaleidoscope.

11. J. Leliaert, B. Van de Wiele, A. Vansteenkiste, L. Laurson, G. Durin, L. Dupre, and B. Van Waeyenberge, Influence of material defects on current-driven vortex domain wall mobility,  Phys. Rev. B 89, 064419 (2014).

12. J. Leliaert, B. Van de Wiele, A. Vansteenkiste, L. Laurson, G. Durin, L. Dupre, and B. Van Waeyenberge, Current-driven domain wall mobility in polycrystalline Permalloy nanowires: a numerical study, J. Appl. Phys. 115, 233903 (2014).

13. J. Leliaert, B. Van de Wiele, A. Vansteenkiste, L. Laurson, G. Durin, L. Dupre, and B. Van Waeyenberge, A numerical approach to incorporate intrinsic material defects in micromagnetic simulations, J. Appl. Phys. 115, 17D102 (2014).