Tunable Domain Wall Chirality By Changing Co/Pt Multilayer Repeat Numbers

The chirality of a magnetic domain wall was modified in ultrathin ferromagnetic Co/Pt multilayer films by varying the repeat number n. Direct observations of field-driven asymmetric wall motion revealed a change in sign of the Dzyaloshinskii-Moriya interaction coefficient from positive (n = 1, 2, and 3) to negative (n = 4), implying the domain wall chirality changes from a left- to right-handed Neel wall. These findings provide a way to control the domain wall chirality in multilayers simply by changing the repeat numbers.