Achiral dipoles on a ferromagnet can affect its magnetization direction

Area of Science:

• Condensed Matter Physics
• Surface Science
• Spintronics

Background:

• Ferromagnetic materials exhibit magnetization that can be influenced by external factors.
• Adsorbed molecules can modify surface properties, but their effect on magnetic anisotropy is less understood.
• Spin-orbit coupling plays a crucial role in spintronic phenomena.

Purpose of the Study:

• To demonstrate a coupling between magnetization direction and adsorbed achiral molecules.
• To elucidate the underlying mechanism of this coupling using theoretical models.
• To explore the potential of achiral molecules in modifying magnetic anisotropy.

Main Methods:

• Utilizing a minimal Stoner model incorporating Rashba spin-orbit coupling.
• Analyzing the influence of an electric field on the ferromagnet surface.
• Extending the Stoner-Wohlfarth model to study magnetic anisotropy.

Main Results:

• Established a coupling mechanism between magnetization direction and adsorbed achiral molecule tilting angle.
• Showed that Rashba spin-orbit coupling is key to this interaction.
• Demonstrated that adsorbed achiral molecules can modify the magnetocrystalline anisotropy of the substrate.

Conclusions:

• Achiral molecules can effectively tune the magnetic anisotropy of ferromagnetic substrates.
• The proposed mechanism provides a theoretical basis for experimental investigations.
• This work encourages further research into current-free chirality-induced spin selectivity.