Seminarium wydziałowe

Dnia 2019-02-19 o godzinie 14:15 w sali 2011 Wydziału Fizyki UwB odbędzie się wykład, na którym dr S. Saha z Laboratory for Mesoscopic Systems, Department of Materials, ETH Zurich i Paul Scherrer Institut, Villigen, Switzerland wygłosi wykład pt:

” Skyrmion Confinement and Damping Modulation in Magnetic Thin Films”

Serdecznie zapraszamy

Andrzej Maziewski

Skyrmion Confinement and Damping Modulation in Magnetic Thin Films

1. Saha^{1, 2}, M. Zelent³, S. Finizio², M. Mruczkiewicz⁴, A. Hrabec^1,2, Z. Luo^{1, 2}, J. Raabe², M. Krawczyk³, P. Gambardella⁵ and L. J. Heyderman^{1, 2}

¹Laboratory for Mesoscopic Systems, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland
²Paul Scherrer Institut, 5232 Villigen, Switzerland
³ Faculty of Physics, Adam Mickiewicz University in Poznan, Umultowska 85, Poznan, PL-61-614 Poland
⁴ Institute of Electrical Engineering, Slovak Academy of Sciences, Dubravska Cesta 9, SK-841-04 Bratislava, Slovakia
⁵Magnetism and Interface Physics, Department of Materials, ETH Zurich, 8093 Zürich, Switzerland

      Magnetic skyrmions [1, 2] are topologically protected nanometer sized chiral spin textures with an out of plane magnetic domain at the center. Due to their various unique features such as stability given by their topology, they are considered as potential candidates for information carriers in next generation data storage devices, like racetrack memory. For such applications, it is crucial to be able to manipulate their current-induced motion in various directions. In this work, we present stable nanoscopic skyrmions confined by an array of antidots. Utilizing the induced periodic potential of the antidot lattice, we propose a method for unprecedented control of the skyrmion dynamics.
     But for that purpose it is also important to understand and control the damping in ferromagnetic thin films. One of the possible ways to manipulate magnetic damping is injection of spin current generated due to spin Hall effect [3] which is an emerging phenomenon where the properties of electrical charge current can be transferred to the electron’s intrinsic angular momentum (spin current), and vice versa. To measure the modulation of damping, we use a time-resolved magneto-optical Kerr effect microscope (TR-MOKE), which has the best spatial and temporal resolution to measure the damping of the ferromagnetic film. The observations will have a strong impact on the development of spintronics devices, such as spin transfer torque nano-oscillators or domain wall racetrack memories.

Acknowledgement:

We acknowledge ETH Zurich Post Doctoral fellowship and Marie Curie actions for People COFUND program and Dr. S. Wintz, Dr. N. S. Bingham, Dr. A. K. Suszka and Mr. T. P. Dao for technical support and valuable discussions.

References:

[1] D.  A. Gilbert et. al., Nat. Commun. 6, 8462 (2015).
[2] O. Boulle et. al., Nat. Nanotech. 11, 449 (2016).
[3] L. Liu et. Al., Science, 336, 555 (2012)