Non-constant geometric curvature for tailored spin-orbit coupling and chirality in superconductor-magnet heterostructures

J Phys Condens Matter. 2024 Mar 14;36(23). doi: 10.1088/1361-648X/ad2e23.

Abstract

We show that tailoring the geometric curvature profile of magnets can be used for bespoke design of an effective non-relativistic spin-orbit coupling, which may be used to control proximity effects if the magnet is coupled to a superconductor. We consider proximity-coupled one-dimensional magnetic wires with variable curvatures, specifically three distinct shapes classified as J-, C-, and S-type. We demonstrate a chirality-dependent spin polarization of the superconducting correlations, and show the role of curvature in determining the ground state of mixed-chirality junctions. We speculate on how this may be implemented in novel device design, and include analysis of its usage in a spin-triplet SQUID.

Keywords: Josephson junctions; chirality; curvilinear magnetism; proximity effect; spintronics; spin–orbit coupling; superconductivity.