Progress in Quantum Communications: Toward a Global Network
In the realm of quantum communications, two research groups have reported progress toward a key milestone – the quantum repeater – paving the way for a quantum-based internet infrastructure. These repeaters are crucial for maintaining the integrity of qubits over extended distances, promising an unprecedented level of secure connectivity, potentially linking vast areas such as different cities or even nations.
Advancing Quantum Connectivity Across Distances
At Harvard University, Can Knaut and his team have successfully established a 35-kilometer span of a quantum network that traverses Boston. This setup includes nodes that possess both a communication qubit and a memory qubit, with the latter capable of preserving quantum states for a duration of up to one second. “Our experiment really put us in a position where we’re really close to working on a quantum repeater demonstration,” Knaut declared.
Meanwhile, Xiao-Hui Bao from the University of Science and Technology of China and his collaborators have entangled nodes spaced by 10 kilometers apart in Hefei. Utilizing cold clouds of rubidium atoms, they have managed to create and synchronize entangled photons. The breakthrough came with the ability to precisely tune the photons’ frequencies at the pivotal central node, something essential for the operation of quantum repeaters.
A Perspective on the Quantum Strides Made
These advancements are meaningful steps forward, compared to the state of quantum internet technologies just ten years prior. Mohsen Razavi of the University of Leeds points out that for a fully functional network to take shape, the entanglement generation rates need to be enhanced. Despite the slow rates of current entanglement, Alex Clark from the University of Bristol is optimistic: “This does point towards a very scalable and large-user-number quantum network.”
The independent research published by these teams hints at the rapid evolution of technologies that can fundamentally alter the landscape of secure communications and computing. Continued research efforts are bringing the concept of a robust, impervious quantum internet closer to reality.
