Quantum coherence and interference of a single moir\'e exciton in nano-fabricated twisted semiconductor heterobilayers

TL;DR

This paper demonstrates the optical observation of quantum coherence and interference of a single moiré exciton in twisted semiconductor heterobilayers, revealing long coherence times and exciton coupling, advancing quantum technology applications.

Contribution

The study introduces a novel nano-fabrication method enabling the observation of single moiré exciton coherence and interference beyond the diffraction limit.

Findings

Single sharp photoluminescence peak from a moiré exciton.

Quantum coherence duration exceeds 10 ps.

Evidence of coupling between excitons in different moiré minima.

Abstract

Moir\'e potential acts as periodic quantum confinement for optically generated exciton, generating spatially ordered zero-dimensional quantum system. However, broad emission spectrum arising from inhomogeneity among moir\'e potential hinders the exploration of the intrinsic properties of moir\'e exciton. In this study, we have demonstrated a new method to realize the optical observation of quantum coherence and interference of a single moir\'e exciton in twisted semiconducting heterobilayer beyond the diffraction limit of light. A significant single and sharp photoluminescence peak from a single moir\'e exciton has been demonstrated after nano-fabrication. We present the longer duration of quantum coherence of a single moir\'e exciton, which reaches beyond 10 ps and the accelerated decoherence process with elevating temperature and excitation power density. Moreover, the quantum interference has revealed the coupling between moir\'e excitons in different moir\'e potential minima. The observed quantum coherence and interference of moir\'e exciton will facilitate potential application toward quantum technologies based on moir\'e quantum systems.