Inducing Dzyaloshinskii-Moriya interaction in symmetrical multilayers using post annealing

Area of Science:

• Condensed Matter Physics
• Materials Science
• Spintronics

Background:

• Interfacial Dzyaloshinskii-Moriya Interaction (iDMI) arises from broken inversion symmetry at ferromagnet/heavy metal interfaces.
• Symmetrical multilayer stacks are not expected to exhibit iDMI.

Purpose of the Study:

• To induce and evidence iDMI in a symmetrical multilayer stack.
• To explore the relationship between interfacial disorder and iDMI strength.
• To demonstrate a method for tuning iDMI in symmetric multilayers.

Main Methods:

• Inducing iDMI via thermal annealing in [Py/Pt]x10 symmetrical multilayers.
• Characterizing iDMI using Brillouin light scattering spectroscopy.
• Analyzing structural changes (crystallinity, roughness) and atomic interdiffusion using first-principles calculations.

Main Results:

• Successfully induced iDMI in the symmetrical [Py/Pt]x10 stack after thermal annealing.
• Observed modified crystallinity and increased surface roughness post-annealing.
• Calculations showed a monotonic increase in iDMI with interfacial disorder caused by atom interdiffusion.

Conclusions:

• Thermal annealing is an effective method to induce iDMI in symmetrical multilayers.
• Interfacial disorder and atom interdiffusion are key factors in inducing iDMI.
• This technique offers a way to tune iDMI for applications in racetrack memories, magnonic devices, and spin-orbitronic elements.