Control of chirality normal to the interface of hexagonal magnetic and nonmagnetic layers

We study the net chirality created by the Dzyaloshinskii-Moriya interaction (DMI) at the boundary between hexagonal layers of magnetic and nonmagnetic materials. It is shown that another mechanism besides elastic torsion is required to understand the change in chirality observed in Dy/Y multilayers during field cooling. This Rapid Communication demonstrates that, due to the overlap between magnetic and nonmagnetic atoms, interfacial steps may produce a DMI normal to the interface in magnetic heterostructures.