Resonant tunneling in graphene-ferroelectric-graphene junctions

We study tunnel junctions consisting of a two-dimensional ferroelectric material sandwiched between graphene electrodes. We formulate a theory for the interplay of the polarization and induced free charges in such devices, taking into account quantum capacitance effects. We predict a gate-sensitive voltage difference across the polar domains, which can be measured using electrostatic force microscopy. Incorporating this electrostatic theory in the tunneling current-voltage characteristics, we identify a resonance peak associated with aligned Dirac cones as a highly sensitive probe of the polarization. This opens the way for device applications with few atom-thick polar layers acting as readable ultra-high-density memory.

Automated summary

We studied tunnel junctions with a two-dimensional ferroelectric material sandwiched between graphene electrodes. By formulating a theory for the interplay of polarization and induced free charges, considering quantum capacitance effects, we predicted a gate-sensitive voltage difference between polar domains. This voltage difference can be measured using electrostatic force microscopy. Incorporating this theory into tunneling current-voltage characteristics, we identified a resonance peak associated with aligned Dirac cones as a highly sensitive probe of the polarization. This opens up possibilities for device applications with thin polar layers for ultra-high-density memory.