Hilary M. Hurst
Affiliations
- Joint Quantum Institute and Condensed Matter Theory Center, Department of Physics, University of Maryland, College Park, MD 20742-4111, USA
Title
- Charged skyrmions on the surface of a three-dimensional topological insulator
Abstract
Three-dimensional topological insulators (TIs) are a new class of materials with robust surface states protected from nonmagnetic disorder. These surface states also exhibit strong spin-momentum locking, which makes their electronic spectrum sensitive to magnetic perturbations. In this talk we consider the interplay between magnetic skyrmions in an insulating thin film and the Dirac surface states of a 3D TI, coupled by proximity effect. The nontrivial magnetic texture of the skyrmions can lead to confinement of Dirac states at the skyrmion radius, where out of plane magnetization vanishes. It is expected that for reasonable experimental parameters skyrmions will have a small number of bound states that can be tuned using an external magnetic field. We argue that these charged skyrmions can be manipulated directly by an electric field, with skyrmion charge and mobility proportional to the number of bound states at the skyrmion radius. Coupling skyrmionic thin films to the Dirac electrons on a TI surface can provide a more direct and efficient way of controlling skyrmion motion in insulating materials. We also comment briefly regarding ongoing research on how other types of magnetic textures can affect the transport properties of 3D TI surface states.
References
- H. M. Hurst, D. K. Efimkin, J. Zang, and V. Galitski, Charged skyrmions on the surface of a topological insulator, Phys. Rev. B 91, 060401(R) (2015).
