Figure 4: Estimated acceleration and deceleration times of domain wall (DW) motion.
(a) Normalized inverse resistance (1/RXX) as a function of the W layer thickness. w and L corresponds to the width and length of the wire. Data are fitted with a linear function (solid line) to obtain the resistivity of W. (b) Spin Hall magnetoresistance 
versus W layer thickness. The solid line shows the fitting result. (c) Spin Hall effective field HSH calculated using the solid line shown in b when a pulse with amplitude of 16 V is applied to the wire. The solid and dashed lines display HSH for ∼5 μm and ∼50 μm wide wires, respectively. The symbols represent values of HSH used to calculate the acceleration time shown in g. (d) The saturation DW velocity (vD) estimated from fitting results of vEND vs. pulse amplitude with Equation (1). (e,f) Calculated DM offset field HDM (e) and the DM exchange constant D (f). (g) W thickness dependence of the acceleration time (τA) and the deceleration time (τD) estimated using equations (2) and (3), respectively. Black squares (circles): τD for 50 μm (5 μm) wide wires, blue diamonds (triangles): τA for 50 μm (5 μm) wide wires. (h) Difference of τD and τA plotted against the W layer thickness. (i) Average DW propagation field HP for ∼5 μm and ∼50 μm wide wires plotted against the W layer thickness. All results are from film set A.
