SPICE Workshop on Quantum Functionalities of Nanomagnets, June 17th - 19th 2025
Alex Petrovic
In non-collinear spin textures such as magnetic skyrmions, the helicity − < 0 ≤ describes the orientation of the local spin rotation axis relative to the helical wavevector. The value of 0 influences the dynamics of skyrmions, as well as their interplay with external electromagnetic fields and ordered states. In particular, the Rashba-Edelstein interaction between a skyrmion and a vortex in a proximate superconductor is suppressed for 0 = ±/2 [1], thus raising the possibility of creating a hybrid topological soliton whose stability is governed by 0. Motivated by the ensuing prospect of building a two-dimensional topological superconducting platform with controllable vortices [2], I will present evidence for helicity switching at superconductor/chiral magnet interfaces, driven by competition between dipolar and Dzyaloshinskii-Moriya (DMI) interactions. For centrosymmetric skyrmion hosts rather than hybrid interfacial systems, the lack of any global DMI creates a near-degenerate helicity landscape, tunable by electric fields and currents. I will also discuss possible techniques for local helicity
control in these materials, with applications in both topological and analog quantum computing [3].
[1] [2] [3] K. M. D. Hals, M. Schecter, and M. S. Rudner, Composite Topological Excitations in
Ferromagnet-Superconductor Heterostructures, Phys. Rev. Lett. 117, 017001 (2016).
A. P. Petrović et al., Skyrmion- (Anti) Vortex Coupling in a Chiral Magnet-Superconductor
Heterostructure, Phys. Rev. Lett. 126, 117205 (2021).
A. P. Petrović, C. Psaroudaki, P. Fischer, M. Garst, and C. Panagopoulos, Colloquium:
Quantum Properties and Functionalities of Magnetic Skyrmions, ArXiv Preprint
2410.11427, (2024).