Negative differential resistance in Van der Waals heterostructures due to moir\'{e}-induced spectral reconstruction

TL;DR

This paper theoretically explores how moiré superlattices in Van der Waals heterostructures can induce negative differential resistance in tunneling transistors due to spectral reconstruction, without requiring momentum conservation.

Contribution

It demonstrates that moiré-induced spectral changes can produce negative differential resistance in heterostructure transistors, expanding understanding of electron transport in these systems.

Findings

Negative differential resistance can arise from moiré superlattice effects.

Spectral reconstruction alters electronic density of states.

Negative differential resistance occurs without momentum conserving tunnelling.

Abstract

Formation of moir\'{e} superlattices is common in Van der Waals heterostructures as a result of the mismatch between lattice constants and misalignment of crystallographic directions of the constituent two-dimensional crystals. We discuss theoretically electron transport in a Van der Waals tunnelling transistor in which one of the electrodes is made of two crystals forming a moir\'{e} superlattice at their interface. By investigating structures containing either the aligned graphene/hexagonal boron nitride heterostructure or twisted bilayer graphene, we show that negative differential resistance is possible in such transistors as a consequence of the superlattice-induced changes in the electronic density of states and without the need of momentum conserving tunnelling present in high-quality exfoliated devices.