Magnetic Interface Anisotropy, Domain Walls, and Skyrmions

Who: Vincent Sokalski, CMU
When: 
Thursday, February 23, 2017 - 4:30pm to 5:30pm
Where: 
Wean Hall 7316, CMU

The recently discovered Dzyaloshinskii-Moriya Interaction (DMI) in thin films has spawned a new direction for magnetism in spintronic application. This phenomenon stabilizes topological magnetic features including skyrmions and chiral domain walls (DWs) that can be manipulated by electric current with unprecedented efficiency. In this talk, I will review consequences of DMI on the structure of “Dzyaloshinskii” DWs and introduce the creep scaling law, which is paramount to describing a range of elastic interfaces including also superconductor flux lines and fluids being absorbed in porous media. Analytic calculations and experimental measurements of domain expansion will be presented to demonstrate that the property governing Dzyaloshinskii DW creep is its elastic stiffness rather than its line energy as widely believed. Along the way, I will introduce some geometric tools in interface thermodynamics including the Wulff construction and the pedal curve that originated from the field of mineralogy, but have been surprisingly useful for describing magnetic domains influenced by DMI.