Title: Chirality-induced Antisymmetry in Magnetic Domain-Wall Speed,
Abstract: In chiral magnetic materials, numerous intriguing phenomena such as built in
chiral magnetic domain walls (DWs) and skyrmions are generated by the
Dzyaloshinskii Moriya interaction (DMI). The DMI also results in asymmetric DW
speed under in plane magnetic field, which provides a useful scheme to measure
the DMI strengths. However, recent findings of additional asymmetries such as
chiral damping have disenabled unambiguous DMI determination and the underlying
mechanism of overall asymmetries becomes under debate. By extracting the
DMI-induced symmetric contribution, here we experimentally investigated the
nature of the additional asymmetry. The results revealed that the additional
asymmetry has a truly antisymmetric nature with the typical behavior governed
by the DW chirality. In addition, the antisymmetric contribution changes the DW
speed more than 100 times, which cannot be solely explained by the chiral
damping scenario. By calibrating such antisymmetric contributions, experimental
inaccuracies can be largely removed, enabling again the DMI measurement scheme.