Breakthrough in Quantum Memory Brings Quantum Internet Closer to Reality

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A recent study has made notable progress in the production, storage, and retrieval of quantum data, moving us closer to developing a quantum internet. Quantum information, carried by qubits, tends to be unstable over long distances, often becoming lost or fragmented during transmission. Effective quantum memory devices are essential for storing and retransmitting qubit states to overcome this challenge, ensuring signal integrity across a network.

The study, conducted by researchers from Imperial College London, the University of Southampton, and German institutions, demonstrates a new method for storing and retrieving photons using standard fibre optic cables. Published in Scientific Advances, the research focuses on improving the storage and retrieval of photons, which are potential carriers of quantum information.

Typically, photons are stored through nonlinear optical frequency conversion or single emitters like quantum dots. The researchers utilized quantum dots, which produce more reliable photons than those produced by nonlinear optics. They successfully matched the wavelength and bandwidth of the photon source with the quantum memory, a critical factor for adequate storage and retrieval. Operating at a wavelength with minimal loss in optical fibres, this advancement is crucial for future quantum networks.

This study builds on earlier work from Stony Brook University, which achieved stable quantum network models at room temperature, enhancing their practical application. The Imperial College study's focus on aligning wavelengths between transmitters and receivers aims to improve transmission efficiency, complementing the Stony Brook study's work on photon storage at room temperature.

The Imperial study also provides a method for long-distance quantum communication using repeaters, which is essential for practical quantum networks. While quantum entanglement theoretically allows for distant communication, implementing it over long distances is challenging. The Stony Brook study supports this by making room temperature quantum information storage cost-effective, paving the way for practical quantum network deployment.