Figure 2: SOF detected with the second-order PHE method.
From: Quantifying interface and bulk contributions to spin–orbit torque in magnetic bilayers
(a) Experimental setup for using the second-order PHE to detect the in-plane magnetization reorientation and the SOF. A transverse field hcal is applied to calibrate the response of the second-order PHE voltage in order to quantify the SOF. (b) Example measured second-order PHE curve of the Ti(1)/CoFeB(0.75)/Pt(5) under several calibration field strengths. The applied dc current is 50 mA. (c) Linear regression algorithm to extract the SOF. The x axis is obtained by ΔVFitting=ΔV(hcal=−270 A m−1)−ΔV(hcal=270 A m−1), and the y axis is ΔV(hcal=0 A m−1) at the corresponding magnetic field. The positively saturated data and negatively saturated data are fitted separately with the average slope taken as the ratio between the total current-induced field and the calibration field. The inset shows the overall curve at both saturated and unsaturated fields. (d) The linear bias current dependence of the SOF indicates that the measurement is still in the linear regime.
