Entanglement Distribution using Optical Quantum Memory Networks

Quantum entanglement is a powerful phenomenon in which particles become deeply linked, even when separated by great distances. This uniquely quantum effect forms the foundation for emerging technologies in secure communication, advanced computing, and precision measurement. However, sharing entanglement across many locations remains a major challenge. This project will develop new methods to reliably generate, store, and distribute entangled particles of light, known as photons, between multiple locations using devices called quantum memories. These memories act like temporary storage for quantum information and are essential building blocks for future quantum networks. By addressing a key barrier to building large-scale quantum systems, this work will help advance the progress of science and open new possibilities for future technologies. The project also contributes to national priorities in education and workforce development by training graduate and undergraduate students in cutting-edge quantum research. Technically, this project addresses a long-standing challenge in entanglement distribution: the mismatch between the broad spectral bandwidth of practical entangled photon sources and the narrow bandwidth of most quantum memories. The research will combine well-established broadband entangled photon sources based on Spontaneous Parametric Down-Conversion (SPDC) with an innovative “loop-based” quantum memory platform that can operate over a much wider frequency range. This hybrid system will enable efficient entanglement distribution across up to five spatially separated memory nodes— a substantial scale-up from existing two-node systems. Key research goals include developing low-loss dual-port loop-based quantum memories, demonstrating quantum interference with stored photons, correcting memory-induced errors, and transferring entangled states among different sets of memory nodes. The results will advance the capabilities of quantum networks and lay the groundwork for future scaling of entanglement distribution technologies. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.