Measurement of spin-orbit torque using field counterbalancing in radial current geometry.

Controlling the direction of magnetization with an electric current, rather than a magnetic field, is a powerful technique in spintronics. Spin-orbit torque, which generates an effective magnetic field from the injected current, is a promising method for this purpose. Here we show an approach for quantifying the magnitude of spin-orbit torque from a single magnetic image. To achieve this, we deposited two concentric electrodes on top of the magnetic sample to flow a radial current. By counterbalancing the current effect with an external magnetic field, we can create a stable circular magnetization state. We measure the magnitude of spin-orbit torque from the stable radius, providing a new tool for characterizing spin-orbit torque.