Deterministic integration of quantum dots into on-chip multi-mode interference beamsplitters using in-situ electron beam lithography

TL;DR

This paper demonstrates a scalable method for precisely integrating quantum dots into on-chip photonic circuits using in-situ electron beam lithography, advancing the development of complex quantum optical networks.

Contribution

It introduces a deterministic, single-step fabrication technique for integrating pre-selected quantum emitters into multi-mode interference beamsplitters on a chip.

Findings

Achieved on-chip single-photon emission with $g^{(2)}(0) = 0.13",

Validated the functionality of the integrated emitter-beamsplitter system.

Abstract

The development of multi-node quantum optical circuits has attracted great attention in recent years. In particular, interfacing quantum-light sources, gates and detectors on a single chip is highly desirable for the realization of large networks. In this context, fabrication techniques that enable the deterministic integration of pre-selected quantum-light emitters into nanophotonic elements play a key role when moving forward to circuits containing multiple emitters. Here, we present the deterministic integration of an InAs quantum dot into a 50/50 multi-mode interference beamsplitter via in-situ electron beam lithography. We demonstrate the combined emitter-gate interface functionality by measuring triggered single-photon emission on-chip with $g^{(2)}(0) = 0.13\pm 0.02$. Due to its high patterning resolution as well as spectral and spatial control, in-situ electron beam lithography allows for integration of pre-selected quantum emitters into complex photonic systems. Being a scalable single-step approach, it paves the way towards multi-node, fully integrated quantum photonic chips.