Regensburg 2022 – wissenschaftliches Programm
KFM 12.5: Vortrag
Dienstag, 6. September 2022, 10:45–11:00, H37
Walking Skyrmions — •Alla Bezvershenko and Achim Rosch — Institute for Theoretical Physics, University of Cologne, 50937 Cologne, Germany
We study the pinning - unpinning transition of the skyrmion lattice in bulk MnSi under applying a slowly oscillating transverse magnetic field. We model the system using an elastic model for skyrmion strings in the presence of pinning forces. With this effective model we show that the presence of a transverse magnetic field reduces the critical current density needed to depin the skyrmion lattice, reaching zero at the critical magnetic field value. Further, the complete phase diagram of this model will be discussed. Below the threshold amplitude, the skyrmion lines stay fully pinned. Upon increasing the amplitude, a so-called "walking" phase starts, where the skyrmion lines start to unpin. If in this phase a sufficiently large electric current is being applied, the skyrmion lattice starts to move. Obtained results are compared to the experimental data on the transverse susceptibility measurements for this system.