Seminaire – Marisel Di Pietro Martinez

Marisel Di Pietro Martinez (Institut Max Plank, Dresden, Allemagne) donnera un séminaire intitulé « Unidirectional motion of topological defects mediating continuous processes«  le 27 novembre à 11h dans l’auditorium de TRT Thales.

Résumé :
Topological defects play a critical role across many fields, mediating processes such as phase transitions and macroscopic behaviors. Key to their properties and potential uses is their motion in real space: their topologically protected nature has generated much attention for their use as robust information carriers. However, until now the controlled motion of topological defects remains challenging, with one dimensional (1D) motion requiring pre-defined tracks defined by one
dimensional structural patterning or magnetic configurations. Here we demonstrate the 1D propagation of topological defects within a laterally unconfined thin film exhibiting a weak magnetic stripe pattern.
Specifically, we find that topological defects in the form of magnetic dislocations move along one-dimensional paths, mediating the rotation of the overall stripe pattern in response to an external magnetic field. We determine the connection between the 1D motion that mediates the two-dimensional rotation process and the underlying three dimensional (3D) magnetic structure by performing 3D magnetic vectorial imaging with the application of in situ magnetic fields. Our multidimensional
approach, combined with phenomenological models, reveals that the characteristic net in-plane magnetization and the stiffness of the stripes are key to realizing this unconfined 1D motion. This work not only establishes the necessary capabilities for the study of the field-driven behavior of topological textures in three dimensions, but also provides a framework for designing materials that utilize this 1D motion