Resistance quantum ($R_K=h/e^2$)

The scale $R_K=h/e^2\simeq 25.8\mathrm{k\Omega }$. Spin degeneracy perfectly transmitting channels instead have conductance $2e^2/h$. Suppressing charge fluctuations in a simple tunnel-island picture requires nanowire junction resistances large relative to $h/e^2$.