Achiral dipoles on a ferromagnet can affect its magnetization direction

TL;DR

This paper explores how achiral molecules adsorbed on a ferromagnet can influence its magnetization direction through a coupling mechanism involving spin-orbit interactions, suggesting new ways to control magnetic properties.

Contribution

It introduces a theoretical model demonstrating how achiral molecules can alter the magnetic anisotropy of a ferromagnet, providing a basis for experimental exploration of chirality effects.

Findings

Achiral molecules can modify the magnetocrystalline anisotropy of a ferromagnet.

The coupling mechanism involves Rashba spin-orbit interaction induced by surface electric fields.

The model suggests potential for controlling magnetization without external magnetic fields.

Abstract

We demonstrate the possibility of a coupling between the magnetization direction of a ferromagnet and the tilting angle of adsorbed achiral molecules. To illustrate the mechanism of the coupling, we analyze a minimal Stoner model that includes Rashba spin-orbit coupling due to the electric field on the surface of the ferromagnet. The proposed mechanism allows us to study magnetic anisotropy of the system with an extended Stoner-Wohlfarth model, and argue that adsorbed achiral molecules can change magnetocrystalline anisotropy of the substrate. Our research's aim is to motivate further experimental studies of the current-free chirality induced spin selectivity effect involving both enantiomers.