Magnetoelectricity of Chiral Micromagnetic Structures

The concept of chirality has profound implications throughout science, from elementary particle physics to biology. In this review, we will refer to chirality as a rotational sense of spin structures such as spin cycloid in spiral magnets, micromagnetic structure in curved magnetic film, twisted spin space of 2D electron gas in an ultrathin magnetic metal film, and micromagnetic structures observed in iron garnet samples. It will be shown that chirality plays the key role in magnetoelectric phenomena observed in iron garnet films: the electric field-induced generation, motion and annihilation of magnetic topological defects such as magnetic bubble domains, domain walls and vertical Bloch lines. As a new degree of freedom that can be controlled by electric and magnetic field, the chirality is an important issue for spintronic applications.