Information : Gate - controlled guiding of electrons in graphene

We note that the inequality expressed by Eq. 4 is consistent with experimental observation (Fig. S1). The inequality in Eq. 4 implies that Ωexp increases with the difference in chemical potentials, i.e. μfi −μi, between the two geometries. Conversely, it means that if the guiding is negligible, then attaching a voltage probe at c would not impact the chemical potential at i i.e. μfi ≈ μi. However, one could also write the Landauer-Büttiker equation for contact c instead. This would give the more familiar form originally used for the “focusing” geometry in Ref. [1],