Quantum-dot-based deterministic photon-emitter interfaces for scalable photonic quantum technology

The scale-up of quantum hardware is fundamental to realize the full potential of quantum technology. Among a plethora of hardware platforms, photonics stands out: it provides a modular approach where the main challenges lie in the construction of high-quality building blocks and in the development of methods to interface the modules. The subsequent scale-up could exploit mature integrated photonics foundry technology to produce small-footprint quantum processors of immense complexity. Solid-state quantum emitters can realize a deterministic photon-emitter interface and enable key quantum photonic resources and functionalities, including on-demand single- and multi-photon-entanglement sources, as well as photon-photon nonlinear quantum gates. In this Review, we use the example of quantum dot devices to present the physics of deterministic photon-emitter interfaces, including the main photonic building blocks required to scale up, and discuss quantitative performance benchmarks. While our focus is on quantum dot devices, the presented methods also apply to other quantum-emitter platforms such as atoms, vacancy centres, molecules and superconducting qubits. We also identify applications within quantum communication and computing, presenting a route towards photonics with a genuine quantum advantage. Quantum photonics offers a scalable approach to advanced quantum-information processing. Based on deterministic photon-emitter interfaces, this Review presents a road ahead for resource-efficient hardware architectures towards applications in quantum communication and quantum computing.

Automated summary

Scaling up quantum hardware is crucial for realizing the full potential of quantum technology, with photonics offering a modular approach and solid-state quantum emitters enabling key quantum functionalities. The use of integrated photonics foundry technology can lead to small-footprint quantum processors, while deterministic photon-emitter interfaces could pave the way for resource-efficient hardware architectures in quantum communication and computing applications.