Two-dimensional topological superconductivity driven by atomic scale spin textures

One of the most promising approaches to the discovery of topological superconductivity is to combine conventional s-wave superconductors with atomic scale spin textures. This approach, based on the building of atomically crafted magnet-superconductor heterostructures (MSHs) [1] is particularly interesting and powerful for two-dimensional (2D) systems, where a plethora of collinear and non-collinear spin textures can be combined with superconducting substrates in order to establish emergent topological superconducting phases.

In the last few years great advancements have been made in the experimental investigation of MSHs where an atomically thin magnetic layer is proximitized to a superconducting substrate [1]. Here, I will discuss how the exchange interaction between a 2D antiferromagnetic spin texture [2,3] or a nanoscale non-collinear spin texture [4] can give origin to topological nodal point superconducting phases, resulting in the formation of chiral edge modes at the boundary of the 2D magnetic islands. In particular, I will explain how the presence of a spin spiral in the 2D magnet offers a new knob for the tuning of the dispersion of the chiral edge modes, something that was newer observed experimentally before and that holds great potential for application in quantum technologies.



[1] R. Lo Conte et al., arXiv:2410.20177 (2024).

[2] R. Lo Conte et al., Physical Review B 105, L100406 (2022).

[3] M. Bazarnik et al., Nature Communications 14, 614 (2023).

[4] R. Brüning et al., arXiv:2405.14673 (2024).

Funding Acknowledgement

Deutsche Forschungsgemeinschaft (DFG) Project No. 459025680.