Experimental Realization of Quantum Memory and EPS-QKD

Quantum Key Distribution (QKD) represents a pivotal protocol for enabling secure communication within a future quantum network. While existing QKD schemes, such as Differential Phase Shift (DPS) and Coherent One-Way (COW) protocols, have advanced secure communication, they also exhibit certain vulnerabilities that can compromise security under practical deployment conditions. Quantum memory is essential for enhancing quantum key distribution (QKD) systems, particularly those using entangled photon sources (EPS QKD) for secure key generation. By enabling the storage and retrieval of quantum states, quantum memory improves security and extends the range of communication, addressing challenges like channel losses. Integrating quantum memory allows for temporal separation between the entanglement source and measurement, facilitating the use of quantum repeaters and improving synchronization. Recent advancements in quantum memory technologies, such as atomic ensembles, have led to better storage times and retrieval efficiencies, making EPS QKD more robust and scalable. In this perspective we recently have developed the first Made in India room temperature warm Rubidium Ensemble based Quantum Memory unit, utilizing the coherent optical non-linear phenomenon of EIT, featuring an electronics-photonics control box and the Optics memory box. Outlining the synergy between Quantum Memory and EPS QKD, emphasizing their potential to transform secure communication we further made a tabletop Entanglement-based QKD (EPS-QKD) demonstration setup, leveraging polarization-entangled photon pairs as the foundation of the secure key exchange.