Modulation of the Dzyaloshinskii–Moriya interaction in Pt/Co/Pt with electric field induced strain

Abstract

The modulation of the interfacial chiral magnetic exchange interaction, i.e., Dzyaloshinskii–Moriya interaction (DMI), is promising to realize ultralow-power information storage or logic devices. Recently, researchers used Brillouin light scattering to demonstrate that mechanical strain can be used to modulate the DMI in Pt/Co/Pt and switch its sign, i.e., the chirality. Toward practical storage applications, here, we utilize electric field-induced strain to modulate the DMI and measure it through asymmetric bubble expansion. The strain is generated by applying an electrical potential over a ferroelectric substrate PMN-PT [011] and then transferred to the ferromagnetic films above. The measurement results show that DMI in Pt/Co/Pt exhibits a butterfly-shaped curve following the strain variation as expected from PMN-PT [011]. The dependence of DMI on strain can be explained using the triatomic model based on the Fert-Levy theory. We find a significant DMI modulation between 0.09 and 0.29 mJ/m2; indeed, no sign switching is observed in our work, which we attribute to the initial state preparation of the film. This work provides a reference for future electric-field controlled ultralow-power spintronic devices.