Bloch Chirality Induced by an Interlayer Dzyaloshinskii-Moriya Interaction in Ferromagnetic Multilayers

Area of Science:

• Condensed Matter Physics
• Materials Science
• Spintronics

Background:

• Chiral spin textures like skyrmions and homochiral domain walls are promising for spintronic devices.
• In thicker films, domain walls mix chiral Néel and achiral Bloch components, reducing demagnetization fields.
• Controlling these mixed textures is crucial for device applications.

Purpose of the Study:

• To investigate the role of interlayer Dzyaloshinkii-Moriya interaction (i-DMI) in controlling Bloch chirality.
• To understand the factors influencing population asymmetry and chiral branching in domain walls.
• To explore the potential for manipulating Bloch chirality in magnetic multilayers.

Main Methods:

• Fabrication of well-ordered Co/Pd multilayers with varying thicknesses.
• Experimental investigation of domain wall structures and chiral properties.
• Theoretical analysis incorporating demagnetization fields and i-DMI.

Main Results:

• Interlayer Dzyaloshinkii-Moriya interaction was shown to break degeneracy between Bloch chiralities.
• Large population asymmetries and chiral branching were observed in the Bloch component of domain walls.
• The observed asymmetry is linked to demagnetization fields, i-DMI, film thickness, and structural ordering.

Conclusions:

• The study demonstrates a method to control Bloch chirality using i-DMI in magnetic multilayers.
• Observed asymmetries provide a pathway for manipulating chiral spin textures.
• This research facilitates the development of advanced spintronic devices by controlling magnetic domain wall chirality.