Tunnel junctions with moir\'{e} superlattice as barrier

TL;DR

This paper develops a unified optical scattering theory to interpret experimental interlayer conductance in moiré superlattices, explaining both background and peak features related to interface potential effects.

Contribution

It introduces a novel optical scattering theory for moiré superlattices that explains experimental conductance features, advancing understanding of interlayer coupling mechanisms.

Findings

Background conductance decreases with interface potential strength.

Conductance peaks are due to scattering resonances.

Theory aligns with experimental observations.

Abstract

Recently, moir\'{e} superlattices have attracted considerable attentions because they are found to exhibit intriguing electronic phenomena of tunable Mott insulators and unconventional superconductivity. These phenomena are highly related to the physical mechanism of the interlayer coupling. However, up to now, there has not existed any theory that can completely interpret the experimental results of the interlayer conductance of moir\'{e} superlattice. In order to solve this problem, the superposition of periods and the corresponding coherence, which are the essential characteristics of moir\'{e} superlattice, should be considered more sufficiently. Therefore, it is quite necessary to introduce optical methods to study moir\'{e} superlattices. Here, we develop a theory for moir\'{e} superlattices which are founded on traditional optical scattering theory. The theory can interpret both the continuously decreasing background and the peak of the interlayer conductance observed in the experiments by a unified mechanism. We show that, the decreasing background of the interlayer conductance arises from the increasing strength of the interface potential, and the peak roots from the scattering resonance of the interface potential. The present work is crucial for understanding the interlayer coupling of the moir\'{e} superlattice, and provide a solid theoretical foundation for the application of moir\'{e} superlattice.