Synthetic antiferromagnet with built-in planar asymmetry

Abstract

Inversion symmetry breaking (ISB) is of great significance in governing many interesting physics. For example, the interfacial Dzyaloshinskii-Moriya interaction (DMI) exists at the heavy metal/ferromagnet (HM/FM) interface with the ISB along the sample normal direction, which holds promises for design and control of chiral spin textures in low-dimensional magnets with efficient current-driven dynamics [1,2]. In this talk, we discuss about a synthetic antiferromagnet (SAF) with built-in planar asymmetry which is attributed to both variable ferromagnetic-layer thickness and the spacer thickness. First we show how the sign and strength of the interlayer exchange coupling (IEC) and magnetic configurations depend on the ferromagnetic-layer thicknesses and the spacer thickness [3]. Interestingly, the IEC can be efficiently modified via changing the ferromagnetic-layer thickness which is essential to advancing magnetic memory and sensing [4] applications with efficient controls. Furthermore, we show the demonstration of the existence of interlayer DMI in our SAF with the built-in planar asymmetry, which supports a chiral magnetization across the SAF. We present the study of current-induced spin-orbit torque (SOT) switching of the chiral magnetization across the SAF and analyse the interlayer DMI’s effects on magnetization and its switching through a combination of experimental and numerical studies [5]. Based on our studies, we will give an outlook of potential applications of our findings in future SOT and domain wall-based devices.