Agenda

Prochain séminaire LANEF/Matériaux Quantiques :

Jeudi 7 novembre 2024 à 14h00

Aaron Müler (ETH Zurich, Switzerland)

“ Simulating the 3D Topology of Multiferroic Manganites “

Pour accéder à ce séminaire :

Institut Néel CNRS, Bâtiment K, Salle Rémy Lemaire  (K223)

Résumé : Ferroic materials with topological defects exhibit unconventional and complex domain patterns, which can take fundamentally different forms for different shapes of the material. A class of examples are hexagonal manganites, improper-ferroelectric multiferroic materials that exhibit vortex-antivortex topological defects. Improper ferroelectrics exhibit primary magnetic or distortive order that drives the electric polarization as a secondary effect. This contrasts with proper ferroelectrics, where the primary order is the electric polarization.  Starting from the Landau theory of symmetry-breaking order parameters and using time-dependent Ginzburg-Landau simulations, we simulate the domain patterns of hexagonal manganites in its ferroelectric and multiferroic phase. We visualize and discuss how their topological defects behave in 2D and 3D and present topological features of its ferroelectric and multiferroic phase that only appear in 3D, such as vortex loops with exceptionally long lifetimes in hexagonal manganites under strain.

Les organisatrices :

Elsa Lhotel (elsa.lhotel@neel.cnrs.fr)
Florence Levy-Bertrand (florence.levy-bertrand@neel.cnrs.fr)