Controlled Formation of Skyrmion Bags

L Lisa‐Marie Kern (Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy 12489 Berlin Germany) V Vladyslav M. Kuchkin (Department of Physics and Materials Science University of Luxembourg Luxembourg L‐1511 Luxembourg) V Victor Deinhart (Ferdinand‐Braun‐Institut (FBH) 12489 Berlin Germany) C Christopher Klose (Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy 12489 Berlin Germany) T Themistoklis Sidiropoulos (Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy 12489 Berlin Germany) M Maike Auer (Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy 12489 Berlin Germany) S Simon Gaebel (Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy 12489 Berlin Germany) K Kathinka Gerlinger (Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy 12489 Berlin Germany) R Riccardo Battistelli (Helmholtz‐Zentrum Berlin für Materialien und Energie GmbH 14109 Berlin Germany) S Steffen Wittrock (Helmholtz‐Zentrum Berlin für Materialien und Energie GmbH 14109 Berlin Germany) T Tamer Karaman (Experimental Physics V Center for Electronic Correlations and Magnetism University of Augsburg 86159 Augsburg Germany) M Michael Schneider (Department of Gynecology and Obstetrics, University Hospital Erlangen) C Christian M. Günther (Technische Universität Berlin Zentraleinrichtung Elektronenmikroskopie 10623 Berlin Germany) D Dieter Engel (Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy 12489 Berlin Germany) I Ingo Will (Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy 12489 Berlin Germany) S Sebastian Wintz M Markus Weigand F Felix Büttner (Helmholtz‐Zentrum Berlin für Materialien und Energie GmbH 14109 Berlin Germany) K Katja Höflich (Ferdinand‐Braun‐Institut (FBH) 12489 Berlin Germany) S Stefan Eisebitt B Bastian Pfau (Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy 12489 Berlin Germany)

Abstract

AbstractTopologically non‐trivial magnetic solitons are complex spin textures with a distinct single‐particle nature. Although magnetic skyrmions, especially those with unity topological charge, have attracted substantial interest due to their potential applications, more complex topological textures remain largely theoretical. In this work, the stabilization of isolated higher‐order skyrmion bags beyond the prototypical π‐skyrmion in ferromagnetic thin films is experimentally demonstrate, which has posed considerable challenges to date. Specifically, controlled generation of skyrmionium (2π‐skyrmion), target skyrmion (3π‐skyrmion), and skyrmion bags (with variable topological charge) are achieved through the introduction of artificially engineered anisotropy defects via local ion irradiation. They act as preferential sites for the field‐ or laser‐induced nucleation of skyrmion bags. Remarkably, ultrafast laser pulses achieve a substantially higher conversion rate transforming skyrmions into higher‐order skyrmion bags compared to their formation driven by magnetic fields. High‐resolution x‐ray imaging enables direct observation of the resulting skyrmion bags. Complementary micromagnetic simulations reveal the pivotal role of defect geometry–particularly diameter–in stabilizing closed‐loop domain textures. The findings not only broaden the experimental horizon for skyrmion research, but also suggest strategies for exploiting complex topological spin textures within a unified material platform for practical applications.

Article Details

Volume / Issue Vol. 37, Issue 29
Published July 01, 2025
ISSN 0935-9648
Publisher Unknown Publisher

Journal Info

Advanced Materials

Unknown Publisher

ISSN: 0935-9648 Physical Sciences

Authors (21)

L

Lisa‐Marie Kern

Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy 12489 Berlin Germany

V

Vladyslav M. Kuchkin

Department of Physics and Materials Science University of Luxembourg Luxembourg L‐1511 Luxembourg

V

Victor Deinhart

Ferdinand‐Braun‐Institut (FBH) 12489 Berlin Germany

C

Christopher Klose

Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy 12489 Berlin Germany

T

Themistoklis Sidiropoulos

Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy 12489 Berlin Germany

M

Maike Auer

Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy 12489 Berlin Germany

S

Simon Gaebel

Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy 12489 Berlin Germany

K

Kathinka Gerlinger

Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy 12489 Berlin Germany

R

Riccardo Battistelli

Helmholtz‐Zentrum Berlin für Materialien und Energie GmbH 14109 Berlin Germany

S

Steffen Wittrock

Helmholtz‐Zentrum Berlin für Materialien und Energie GmbH 14109 Berlin Germany

T

Tamer Karaman

Experimental Physics V Center for Electronic Correlations and Magnetism University of Augsburg 86159 Augsburg Germany

M

Michael Schneider

Department of Gynecology and Obstetrics, University Hospital Erlangen

C

Christian M. Günther

Technische Universität Berlin Zentraleinrichtung Elektronenmikroskopie 10623 Berlin Germany

D

Dieter Engel

Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy 12489 Berlin Germany

I

Ingo Will

Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy 12489 Berlin Germany

S

Sebastian Wintz

M

Markus Weigand

F

Felix Büttner

Helmholtz‐Zentrum Berlin für Materialien und Energie GmbH 14109 Berlin Germany

K

Katja Höflich

Ferdinand‐Braun‐Institut (FBH) 12489 Berlin Germany

S

Stefan Eisebitt

B

Bastian Pfau

Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy 12489 Berlin Germany