Resonant tunneling in graphene-ferroelectric-graphene junctions

TL;DR

This paper presents a theoretical study of graphene-ferroelectric-graphene tunnel junctions, revealing a resonance feature that can be used for ultra-high-density memory applications by detecting ferroelectric polarization.

Contribution

It develops a quantum capacitance-based electrostatic theory for FE-graphene junctions and predicts a gate-sensitive resonance peak linked to FE polarization.

Findings

Resonance peak correlates with FE polarization.

Gate voltage controls FE voltage difference.

Potential for ultra-high-density memory devices.

Abstract

We study tunnel junctions consisting of a two-dimensional ferroelectric (FE) material sandwiched between graphene electrodes. We formulate a theory for the interplay of the FE polarization and induced free charges in such devices, taking into account quantum capacitance effects. We predict a gate-sensitive FE voltage difference across the device, 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 FE polarization of the junction. This opens the way for device applications with few atom-thick FE layers acting as readable ultra-high-density memory.