Tuning Dzyaloshinskii-Moriya interactions in magnetic bilayers with a ferroelectric substrate

We performed systematic first-principles calculations to explore the possibility of manipulating Dzyaloshinskii-Moriya interactions (DMIs) in heavy metal/ferromagnetic metal bilayers with ferroelectric (FE) polarization of a $\mathrm{PbTi}{\mathrm{O}}₃$ (PTO) substrate. Significantly, both the sign and magnitude of the DMI can be tailored by the FE polarization reversal in PTO. Moreover, the DMIs of Ir/Co/PTO and Ir/Fe/PTO can achieve large values ($|d|>10\phantom{\rule{0.16em}{0ex}}\mathrm{meV}$) under the influence of an upward electric polarization of PTO. Our findings provided useful strategies for enhancing and tailoring DMIs in complex heterostructures and paved the way for the development of DMI-based devices with ultralow power consumption.