Scalable deterministic integration of two quantum dots into an on-chip quantum circuit

TL;DR

This paper demonstrates a scalable on-chip quantum photonic circuit integrating two quantum dots with high purity, a 50/50 beam splitter, and deterministic placement, advancing the development of scalable quantum information systems.

Contribution

It presents a monolithic prototype of an integrated quantum photonic circuit with deterministic quantum dot integration and functional beam-splitting, a significant step toward scalable quantum photonic devices.

Findings

Successful deterministic integration of two quantum dots into nanobeam cavities.

Achieved a nearly 50/50 splitting ratio in the on-chip beam splitter.

Quantum emitters exhibit high single-photon purity enabling on-chip experiments.

Abstract

Integrated quantum photonic circuits (IQPCs) with deterministically integrated quantum emitters are critical elements for scalable quantum information applications and have attracted significant attention in recent years. However, scaling up them towards fully functional photonic circuits with multiple deterministically integrated quantum emitters to generate photonic input states remains a great challenge. In this work, we report on a monolithic prototype IQPC consisting of two pre-selected quantum dots deterministically integrated into nanobeam cavities at the input ports of a 2x2 multimode interference beam-splitter. The on-chip beam splitter exhibits a splitting ratio of nearly 50/50 and the integrated quantum emitters have high single-photon purity, enabling on-chip HBT experiments, depicting deterministic scalability. Overall, this marks a cornerstone toward scalable and fully-functional IQPCs.