Equilibrium shapes and dynamic behavior of chiral magnetic domains

Magnetism has had a profound effect on our everyday lives from compass needles in ancient times to modern hard disc drives in today’s computers. The existence of magnetic materials is rooted in the Heisenberg exchange interaction energy, which favors parallel (or anti-parallel) alignment of neighboring spin vectors and their associated magnetic dipole moments as found, for example, in Fe, Ni, and Co. A lesser-known type of magnetic exchange called the Dzyaloshinskii-Moriya Interaction (DMI) instead favors an orthogonal alignment. The combination of these two effects leads to unusual magnetic configurations characterized by a chiral winding of the internal magnetization; a type of order very different than that found in a conventional ferromagnet. In this presentation, I will introduce the most important concepts in chiral magnetism before elaborating on how principles of thermodynamics and symmetry can be leveraged to explain unusual behavior of 2D magnetic bubbles and domain walls.