Fig. 3: Cu thickness dependence experiments.
From: Nonlocal electrical detection of reciprocal orbital Edelstein effect
a Schematic illustration of lateral and vertical OAM distribution and the role of oxidized and unoxidized Cu. The top Cu layer is oxidized and homogenous (CuOx region), assisting the long-range orbital response; the bottom Cu layer remains unoxidized (Cu region), exhibiting a short vertical decay length of orbital accumulation. In a nonlocal configuration, orbital accumulation distributes laterally and vertically. b, c Cu thickness dependence results of 2ΔRDOEE (b) and 2ΔRIOEE (c). The results are measured at room temperature with FM = Co25Fe75. The solid curves represent the fitting of the data to Eq. (1). The error bars in b, c indicate the standard deviation of R after the magnetization is saturated. d λo at various Cu thicknesses estimated from fitting, whose values are almost constant. The dotted line marks the value of λo = 100 nm. e Fitting result of parameter A. The solid curves show the exponential fitting for A. The vertical decay length of orbital accumulation (\({\lambda }_{{{{\rm{o}}}}}^{z}\) ~ 25 nm) is much smaller than the lateral one (λo ~ 100 nm), suggesting a distinction between lateral and vertical distribution of OAM. Error bars in d, e represent 95% confidence intervals from fitting results. All the results agree with Onsager’s reciprocal relations.
