Extended Data Fig. 2: Characterization of device B.

a, Scanning electron micro-graph of device B, used to obtain the measurements presented in Fig. 2. Scale bar shown is 100 nm. b–c, Coulomb diamond measurements of the left and right QDs. Charging energies are extracted to be 1.4 meV. The lever arm α_N is extracted to be about 0.11 for each QD. This lever arm is used for the extraction in Fig. 2d. d–e, To validate the direction of B_SO and to show the connection between interactions in strongly coupled QDs and underlying ECT and CAR processes, we first measure ECT and CAR currents in the weakly coupled dots, as detailed in²⁹. With B⊥B_SO, measurements of CAR (d) and ECT (e) show the typical blockades for same-spin and opposite-spin charge configurations respectively. In f–g, with B∥B_SO, the spin non-conserving ECT and CAR processes are observed to be revived. h, Measuring CAR and ECT rates as a function of magnetic field angle θ shows the currents for the spin non-conserving processes are indeed smoothly controlled and become suppressed when θ = 0. This supports the interpretation that B∥B_SO when B is perpendicular to the 1-D channel. i–j, Next, the QDs are operated with higher tunnelling rates between the QDs and the SC, to enable strong couplings. Similar to Fig. 1e-f, CSDs are obtained in the strongly interacting regime, taken with the verified B∥B_SO and B⊥B_SO respectively.