A PAckageD source of Multiplexed Entangled photons (PADME)

**Quantum technologies (QT)** are transforming our economy and education. Slowly but steadily delivering novel capabilities to secure communications, measure undetectable signals, and in a not-so-far future, revolutionise computing.

Light plays a pivotal role as a carrier for quantum signals and as the interface between the new quantum hardware and the available technology. For example, entangled photons -- light particles strongly connected even when far apart -- can be routed over the available fibre network and are required in several quantum cryptographic schemes and all-optical quantum computers. For light to fulfil its mission as quantum herald, we need to embed it in a compact, scalable, and mass-producible platform.

With PADME, we propose investigating **Photonic Integrated Circuits (PICs)** as a source of quantum states of light, following the steps that brought electronics to today's consumer market a few decades ago.

We will study how to generate and extract entangled photons from a PIC component of our own design and fabricated by a commercial foundry. We will combine our in-house photonics and optoelectronics packaging know-how (Bay Photonics), years of academic research excellence (Universities of Strathclyde and Glasgow), and the most recent advances of commercial PIC foundries to deliver a high-performance, compact, and reliable source of entangled photon pairs that will service a global market and bolster the UK's position as a world-leader in quantum and photonic innovation.

We expect this feasibility study to stimulate further R&D and market awareness into adopting the PIC approach for quantum technologies and developing a national quantum PIC supply chain.