Interfacial Dzyaloshinskii-Moriya interaction between ferromagnetic insulator and heavy metal

Recent demonstration of the interfacial Dzyaloshinskii-Moriya interaction (DMI) between a heavy metal and a magnetic insulator provides the possibility to manipulate chiral spin textures in the magnetic insulator for the extremely low power consumption devices. However, the origin and strength of the interfacial DMI remain in dispute in this system. We used the electrical transport measurements to determine the DMI strength to be similar to 0.040 pJ/m at room temperature in Pt/Tm3Fe5O12 (TmIG) bilayers. The TmIG saturation magnetization and DMI strength exhibit different temperature dependences, which is attributed to the DMI being mainly contributed by Fe ions instead of Tm ions. With a Cu layer inserted between Pt and TmIG, the DMI strength is reduced to similar to 0.012 pJ/m and the topological Hall effect vanishes, strongly suggesting that the Pt/TmIG interface has important contribution to the DMI.