Dynamic Symmetry Breaking in Chiral Magnetic Systems
Abstract
The Dzyaloshinskii–Moriya interaction (DMI) in magnetic systems stabilizes spin textures with preferred chirality, applicable to next‐generation memory and computing architectures. In perpendicularly magnetized heavy‐metal/ferromagnet films, the interfacial DMI originating from structural inversion asymmetry and strong spin‐orbit coupling favors chiral Néel‐type domain walls (DWs) whose energetics and mobility remain at issue. Here, a new effect is characterized in which domains expand unidirectionally in response to a combination of out‐of‐plane and in‐plane magnetic fields, with the growth direction controlled by the in‐plane field strength. These growth directionalities and symmetries with applied fields cannot be understood from static treatments alone. The authors theoretically demonstrate that perpendicular field torques stabilize steady‐state magnetization profiles highly asymmetric in elastic energy, resulting in a dynamic symmetry breaking consistent with the experimental findings. This phenomenon sheds light on the mechanisms governing the dynamics of Néel‐type DWs and expands the utility of field‐driven DW motion to probe and control chiral DWs.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Aug 06, 2021
- Source ID
- 10.1002/adma.202101524
Entities
People
- Eric E Fullerton
- Grant A. Riley
- Hans T. Nembach
- Jeffrey Brock
- Marc De Graef
- Maxwell P Li
- Michael D. Kitcher
- Pierre Vallobra
- Rajasekhar Medapalli
- Stéphane Mangin
- Vincent Sokalski
Organizations
- Carnegie Mellon University
- Defense Advanced Research Projects Agency
- Office of Basic Energy Sciences
- University of California, San Diego
- University of Colorado
- University of Lorraine