TRR 360 Seminar:Multiferroic conversionTsuyoshi Kimura
2025-12-17 16:00 - 17:00 (Europe/Berlin) | University of Augsburg, Room 242-R
Multiferroic conversion

Prof. Dr. Tsuyoshi Kimura
Department of Applied Physics, University of Tokyo, Japan

Symmetry breaking ascribed to the evolution of an order parameter is one of the most important concepts in materials physics. Representative examples are symmetry breakings in ferroic materials, such as the symmetry breaking of time reversal in ferro-magnets and that of space inversion in ferroelectrics. Recent research developments of multiferroic materials have triggered extensive studies on unconventional ferroic materials such as ferro-toroidic, ferro-axial, and ferro-chiral materials.

In this presentation, we propose the concept of “multiferroic conversion”, which refers to the transformations of ferroic states by combining different ferroic orders. Such conversion occurs, for example, by a deformation of a structural unit in a ferroic material [1] and by the application of external stimuli such as an electric field to a ferroic material [2-5]. We demonstrate several types of multiferroic conversion by observing unconventional optical phenomena, including electric-field-included Faraday effect (from ferro-magnetic-monopolar to ferro-magnetic state) [2], electrogyration (ferro-axial to ferro-chiral) [3], magneto-chiral dichroism (ferro-axial to ferro-magnetic-toroidal) [4], and electric-field-induced nonreciprocal directional dichroism (altermagnetic to ferro-magnetic-toroidal) [5]. The concept of multiferroic conversion will lead to the unconventional functionalities of various ferroic materials.

[1] T. Nagai et al., J. Am. Chem. Soc. 146, 23348 (2024).[2] T. Hayashida et al., Phys. Rev. Research 4, 043063 (2022).[3] T. Hayashida et al., Nat. Commun. 11, 4582 (2020).[4] T. Hayashida et al., Proc. Natl. Acad. Sci. 120, e2303251120 (2023).[5] T. Hayashida et al., Adv. Mater. 37, 241876 (2025).

Venue
