Fig. 3: Control experiments confirming a quasiparticle mediated Rashba–Edelstein effect.
From: Phase biasing of a Josephson junction using Rashba–Edelstein effect
a Comparison of low temperature resistance(R(T)) of an Nb(150 nm)-[Pt(50 nm)/Cu(100 nm)]-Nb(150 nm) JJ (open symbols) and Nb(150 nm)-Pt(50 nm)-Nb(150 nm) JJ(solid symbols)measured with a bias current of 10 μA. The junction without Cu-layer does not show any proximatisation. Inset shows the IV characteristics for both junctions at zero field. Nb-(Pt/Cu)-Nb junction shows a critical current ~200 μA. The inset EDAX elemental maps for both these junctions clearly show the absence of Cu in the Nb-Pt-Nb junction, as represented in the device schematics. b R(T) plot for an Nb-(Pt(30 nm)/Cu)-Nb junction is shown on the right-hand axis along with the temperature dependence of ΔH on the left-hand axis, shows a direct connection between quasiparticle current and ΔH. The ΔH values were extracted from V(H) curves measured at the respective temperatures with 200 μA current. c The voltage response of the Nb-(Pt(30 nm)/Cu)-Nb junction shows a ΔH of 4mT. Partial thinning of the Pt layer under the junction area in the same device did not change ΔH, as shown in panel (d). The false coloured FESEM image of the device and the schematic are inset in the respective panels, along with the IV curves.
