Analyzing polarity-averaged effects in spin-orbit torques via asymmetric hysteresis loop shifts

Abstract

Averaged observations of physical phenomena have been utilized for comprehending specific occurrences in nature; however, these may overlook the crucial characteristics of individual events, thereby leading to diverse conclusions. For example, individual wave occurrences such as superposition and interference yield markedly divergent outcomes when viewed in detail. Similarly, this study enhances the comprehensive framework of spin-orbit torque (SOT) within the hysteresis loop shift measurement by employing the average of effective magnetic fields arising from two distinct magnetic reversals. This approach facilitates the presentation of a physically descriptive SOT model, previously characterized only by single chiral domain-wall (DW) polarity qualitatively. By integrating this model with established measurement methodologies and theoretical paradigms, we advance a theoretical framework based on the magnetic DW chirality of individual DW polarities and aim to elucidate the phenomena of SOT with clarity. The anticipated outcomes include the rectification of inaccuracies in widely employed measurement methodologies and the enhancement of our comprehension of the fundamental physics, which are expected to propel advancements in next-generation spintronics materials and devices.