In a groundbreaking development, scientists have achieved a significant milestone in building a “quantum internet” by creating a network of “quantum memories” operating at room temperature. The researchers successfully stored and retrieved two photonic qubits – quantum bits made from photons – marking a pivotal step towards the realization of a quantum internet.

Published in the Nature journal, Quantum Information, on January 15, the study emphasizes the importance of quantum memory as a foundational technology for the future quantum internet. Quantum memory, akin to classical computing memory, stores data as qubits, allowing for a superposition of 1 and 0. Quantum computers, with millions of entangled qubits, are anticipated to outperform current supercomputers by enabling simultaneous calculations.

The quantum internet relies on quantum mechanics to transmit data between quantum computers, and quantum memory is a key component for its functionality. Unlike classical computing, where data is encoded in binary states of 1 or 0, quantum memory’s superposition capabilities enable denser information storage and transmission.

Lead author Eden Figueroa, a professor of physics and astronomy at Stony Brook University, highlighted the significance of the breakthrough, stating, “To get these fleets of quantum memories to work together at a quantum level, and in a room temperature state, is something that is essential for any quantum internet on any scale. To our knowledge, this feat has not been demonstrated before, and we expect to build on this research.”

Unlike previous quantum networks requiring cooling to absolute zero, the researchers achieved room temperature quantum memory by storing photons in rubidium gas. While the stored photons lasted only for a fraction of a second in this experiment, the room temperature aspect enhances the viability of future quantum internet designs.

The unique ability to interfere with two independently stored photons simultaneously, creating a quantum signature known as the Hong-Ou-Mandel dip, showcases the experiment’s success. Although the storage duration was brief compared to cryogenic temperatures, the breakthrough opens possibilities for faster and more practical quantum communications.

Quantum communications are inherently secure, as any attempt to intercept or manipulate information collapses the superposition of qubits, providing an active field for research. The next phase involves developing methods for detecting when a quantum signal is ready for retrieval without direct observation, paving the way for quantum repeaters and, eventually, a large-scale quantum internet.

As the scientific community races to develop the technologies required for a quantum internet, this achievement contributes significantly to the ongoing progress in quantum communication and networking.


thanks to Thomas Frey for the link: