The DeQD project is poised to tackle a significant bottleneck in scaling photonic quantum computing by innovating on single-photon demultiplexing technology. Photonics offers an attractive platform for quantum computing, with single photons serving as quantum bits (qubits). Quantum dots, in particular, enable the generation of high-quality single photons at an impressive rate of 10⁹ Hz. However, current systems require intricate demultiplexing setups to separate these sequentially emitted photons into distinct quantum channels. This process introduces challenges such as efficiency loss, temporal synchronization, and handling of increasing photon inputs, all of which the DeQD project seeks to resolve.

The core innovation of the DeQD initiative lies in its development of an integrated photonic chip capable of synchronously emitting multiple indistinguishable photons. This approach addresses the limitations of probabilistic methods like parametric down-conversion and reduces the complexity of traditional demultiplexing setups. By designing a platform for on-chip photon generation and manipulation, DeQD ensures minimal noise, reduced decoherence, and efficient scaling, thus advancing photonic quantum computers closer to achieving quantum advantage.

In addition to technical breakthroughs, DeQD bridges a critical gap in quantum material fabrication within the Danish quantum ecosystem. Leveraging advanced molecular beam epitaxy (MBE) systems, the project facilitates high-precision fabrication of quantum components, offering resources to both academic and commercial partners. This infrastructure promotes collaboration and sets a foundation for standardization within Denmark’s quantum technology strategy.

The project exemplifies multidisciplinary collaboration, uniting expertise from universities, government technology institutes, and private companies across two countries. This collective effort aligns with Denmark’s national quantum strategy, which emphasizes the importance of joint ventures and standardized approaches. By addressing foundational challenges in quantum hardware and fostering partnerships, DeQD is well-positioned to accelerate progress in quantum computing and its transformative applications in fields such as climate modeling, energy optimization, and personalized medicine.