Realisation and measurement of on-demand entangled photon pair sources enabled by fully two-dimensional material heterostructures.

Objective

The generation of entangled photons underpins quantum communication, quantum computing, and secure information transfer, as such photons exhibit reduced susceptibility to loss and environmental decoherence, enabling reliable transmission over long distances. However, existing sources—primarily based on nonlinear crystals or quantum dots—face significant limitations, including low efficiency, limited scalability, and lack of on-demand tunability. A promising alternative involves converting electron Cooper pairs directly into photon pairs, offering potentially higher entanglement generation rates. Recent advances have demonstrated this concept using molecular beam epitaxy-grown hybrid structures, yet these approaches remain labor-intensive and cost-prohibitive. The Superconducting Light-Emitting Diode (SLED) project addresses these limitations by developing a platform for deterministic entangled photon generation. SLED combines magic-angle twisted bilayer graphene (MATBG), with a two-dimensional WSe2 semiconductor. Cooper pairs from MATBG are injected into the WSe2 channel, where the electron and hole cooper pair will recombine to emit photon pair ,with high fidelity, on-demand tunability, and energy-efficient operation at cryogenic temperatures. The ability to switch between SLED operation and conventional LED operation entirely through electrostatic gating, without requiring any structural or cryogenic modifications. This tunability enables real-time control over the quantum state of emitted photons, providing a versatile platform for both classical optoelectronics and quantum photonics within a single device.The project aims to deliver a deterministic platform for entangled photon generation, establishing a foundational pathway toward next-generation integrated quantum photonic architectures and enabling transformative advances in quantum communication and computation.