Advancements in Quantum Repeater Technology Leading to Quantum Internet

Researchers are making significant progress in developing quantum repeaters, a crucial component for building a secure quantum internet.

Efforts to establish a global quantum internet have seen remarkable advancements in quantum information storage, moving towards secure communication over vast distances. The traditional internet transmits data using binary bits (0s and 1s) through electrical or optical signals. In contrast, a quantum internet utilizes quantum bits (qubits) that leverage the quantum property of entanglement, allowing instantaneous influence over particles regardless of distance.

Sending entangled qubits across long distances necessitates a quantum repeater, a device capable of storing entangled states in memory and reproducing them for further transmission, crucial for maintaining data integrity.

Recent achievements by two research teams in establishing long-lasting entanglement memory in quantum networks mark significant progress towards developing quantum repeaters. One team from Harvard University led by Can Knaut demonstrated a quantum network spanning 35 kilometers in Boston, showcasing the ability to store quantum states in memory for up to a second. This groundwork brings them closer to constructing a functional quantum repeater in the near future.

Another team, led by Xiao-Hui Bao at the University of Science and Technology of China, successfully entangled three nodes separated by 10 kilometers each in Hefei. By using supercooled rubidium atom clouds to generate entangled photons, they laid the foundation for coordinating photons to link various nodes, a key feature for quantum repeaters connecting different locations.

Although significant progress has been made, continuous advancements are necessary to improve entanglement generation rates for a fully operational quantum network. Researchers emphasize the need for refining both quantum and classical network engineering aspects to enhance efficiency and reduce losses in entanglement rates.

The journey towards a scalable quantum network with quantum repeaters remains ongoing, with the current developments laying a solid foundation for future breakthroughs in quantum communication technologies.

Journal reference: Nature DOI: 10.1038/s41586-024-07252-z

Journal reference: Nature DOI: 10.1038/s41586-024-07308-0