Microscopic origin of chirality-dependent magnetic interactions

Identify the microscopic origin of the molecular chirality-dependent interaction that modifies the magnetic properties of adjacent ferromagnetic layers, and develop quantitative analyses of this interaction.

Background

The paper studies chirality-induced magnetic effects in heterostructures where chiral polypeptides are separated from a ferromagnetic multilayer by insulating MgO spacer layers. Earlier experiments had reported changes in magnetic anisotropy, magnetization curves, switching behavior, and skyrmion stability after adsorption of chiral molecules, but the physical origin of these effects had not been established quantitatively. The present work directly measures an enantiomer-dependent effective magnetic field and rules out direct electronic coupling as its origin, while discussing possible mechanisms involving interfacial spin polarization and chiral-phonon-mediated spin-lattice coupling. A complete microscopic explanation and quantitative theory therefore remain unresolved.

References

While these observations indicate a molecular chirality-dependent interaction, its origin remains unclear, and quantitative analyses are lacking.

— Direct Quantification of Molecular Helicity-Dependent Effective Magnetic Fields in Chiral Polypeptide/Ferromagnet Heterostructures  (2610.12145 - Balland et al., 8 Oct 2026) in Section I, Introduction