Moir\'e excitons: from programmable quantum emitter arrays to spin-orbit coupled artificial lattices

TL;DR

This paper explores how moiré patterns in 2D semiconductor heterostructures create tunable, long-lived exciton superlattices with complex topological properties, enabling programmable quantum emitters and artificial lattices for quantum physics applications.

Contribution

It demonstrates the realization of tunable exciton superlattices with spin-orbit coupling and topological features driven by moiré effects in 2D heterostructures, a novel approach for quantum emitter arrays.

Findings

Moiré patterns create superstructures of nanodots for long-lived excitons.

Electric and strain tuning enable control over emission and spin properties.

Exciton bands exhibit Dirac and Weyl nodes with topological edge modes.

Abstract

Highly uniform and ordered nanodot arrays are crucial for high performance quantum optoelectronics including new semiconductor lasers and single photon emitters, and for synthesizing artificial lattices of interacting quasiparticles towards quantum information processing and simulation of many-body physics. Van der Waals heterostructures of 2D semiconductors are naturally endowed with an ordered nanoscale landscape, i.e. the moir\'e pattern that laterally modulates electronic and topographic structures. Here we find these moir\'e effects realize superstructures of nanodot confinements for long-lived interlayer excitons, which can be either electrically or strain tuned from perfect arrays of quantum emitters to excitonic superlattices with giant spin-orbit coupling (SOC). Besides the wide range tuning of emission wavelength, the electric field can also invert the spin optical selection rule of the emitter arrays. This unprecedented control arises from the gauge structure imprinted on exciton wavefunctions by the moir\'e, which underlies the SOC when hopping couples nanodots into superlattices. We show that the moir\'e hosts complex-hopping honeycomb superlattices, where exciton bands feature a Dirac node and two Weyl nodes, connected by spin-momentum locked topological edge modes.