Fig. 3.

Experimental analysis of spin-polarized transport during elongation of Ag/vanadocene junctions. a Fano factor versus conductance during the elongation of two different Ag/vanadocene junctions. Following each measurement, the junction is stretched by 0.1–0.05 Å. The uncertainty, corresponding to systematic errors in our measurements, is comparable to the symbols’ diameter, as shown in Supplementary Fig. 4. Inset, lower bound for CSP (P is the minimal P_G), as determined by the experimentally obtained Fano factor and conductance, with ±3% experimental uncertainty. b Total conductance (black dots, error range is given by dots’ diameter) and transmission probabilities of the largest four spin-polarized transmission channels (colors). The large uncertainty in the transmission probabilities, indicated by the error bars, stems from the numerical analysis (Supplementary Note 5). As the junction is stretched, the conductance evolves towards the upper limit of ballistic spin-polarized transmission, with conductance approaching $G_0^{\mathrm{s}}$, spin-polarization approaching 100%, and electron transport that is dominated by a single spin-polarized transmission channel (red-shaded). Here, the maximal values are: G = 0.98 ± 0.01 $G_0^{\mathrm{s}}$, P_G ≥ 95 ± 3%, with significant suppression of all spin channels except one. Additional examples for the evolution of transport properties as a function of junction elongation appear in Supplementary Fig. 7. See also Supplementary Note 6.