Tunable interfacial Dzyaloshinskii-Moriya interaction in symmetrical Au/[Fe/Au]n multilayers

The interfacial Dzyaloshinskii-Moriya interaction (i-DMI) has been exploited in as-made symmetrical Au/[Fe/Au](n) structures. By tailoring the chirality of the i-DMI at the Au/Fe interface, an overall enhancement of the i-DMI can be obtained in such a symmetrical structure. Furthermore, the tunability of the i-DMI was realized by changing the stacking number n. Compared to the top of Fe, a large tensile stress at the bottom of Fe due to lattice mismatch was responsible for the chirality change in the sub/Au/Fe system. Layer-resolved DMI calculations revealed that the sign of the spin-orbit coupling (SOC) energy was changed for Au near the interface of Au/Fe under tensile stress, subsequently reversing the chirality of the i-DMI from left-handed to right-handed. Our findings provide a simplest way to tune the i-DMI in a multilayer system, further benefiting the application of skyrmion-based devices.

Automated summary

In this study, the interfacial Dzyaloshinskii-Moriya interaction (i-DMI) was utilized to enhance the overall i-DMI in symmetrical Au/[Fe/Au](n) structures. By controlling the chirality at the Au/Fe interface and changing the stacking number, the tunability of i-DMI was demonstrated. The chirality change was attributed to a large tensile stress at the bottom of Fe due to lattice mismatch, leading to a reversal of the i-DMI chirality from left-handed to right-handed in a multilayer system.