Oscillation of Dzyaloshinskii–Moriya interaction driven by weak electric fields

Abstract

Dzyaloshinskii–Moriya interaction (DMI) is under extensive investigation considering its crucial status in chiral magnetic orders, such as Néel-type domain wall (DW) and skyrmions. It has been reported that the interfacial DMI originating from Rashba spin–orbit coupling (SOC) can be linearly tuned with strong external electric fields. In this work, we experimentally demonstrate that the strength of DMI exhibits rapid fluctuations, ranging from 10% to 30% of its original value, as a function of applied electric fields in Pt/Co/MgO heterostructures within the small field regime (< 10−2 V/nm). Brillouin light scattering (BLS) experiments have been performed to measure DMI, and first-principles calculations show agreement with this observation, which can be explained by the variation in orbital hybridization at the Co/MgO interface in response to the weak electric fields. Our results on voltage control of DMI (VCDMI) suggest that research related to the voltage control of magnetic anisotropy for spin–orbit torque or the motion control of skyrmions might also have to consider the role of the external electric field on DMI as small voltages are generally used for the magnetoresistance detection.