Spin-driven Multiferroics

This lecture explores the concept of multiferroics, focusing on spin-driven mechanisms and the magnetic control of ferroelectric polarization. It discusses the inverse Dzyaloshinskii-Moriya interaction, exchange striction, and d-p hybridization in type II multiferroics. The presentation delves into the breaking of spatial symmetry by magnetic order and the unique properties of materials like TbMnO3 and Ca3Co2MnO6. Theoretical models for the magnetoelectric effect and the role of spin supercurrent in noncollinear magnets are also covered, along with the discovery of collinear-magnetism-driven ferroelectricity. The lecture further examines the ferroelectric behavior in Ising chain magnets and the influence of exchange striction on symmetry breaking, providing insights into the complex interplay between magnetic and electric properties.