Electron transport in a bilayer graphene/layered superconductor NbSe₂ junction: effect of work function difference

We have experimentally studied electron transport in a bilayer graphene (BLG)/layered superconductor NbSe₂ junction encapsulated with hexagonal boron nitride. The junction exhibits nonlinear current-voltage characteristics which strongly depend on the gate voltage around the charge neutrality point (CNP) of the BLG. Besides, we observe that the gate voltage dependence of electron transport in the BLG portion close to the junction interface is different from that of the BLG portion apart from the interface, indicating that the spatial variation of the Dirac point in the charge transfer region due to the difference in work function between superconductor and graphene needs to be considered in the analysis of the superconducting proximity effect.