Quantum teleportation allows quantum information to be transferred to a remote location by using quantum entanglement and classical communication. This has been achieved with different rates of independent quantum light photons, from tabletop experiments to real-world demonstrations.
Using the low-Earth orbit Micius satellite, researchers have now achieved quantum teleportation at 1200 km. Until now there is no quantum teleportation system whose rate can reach the order of hertz, which will hinder future applications of the quantum internet.
In a paper published in Light: Science and Applicationsa group of scientists led by Prof. Guangcan Guo and Prof. Qiang Zhou from the University of Electronic Science and Technology of China (UESTC), collaborated with Prof. Lixing You from the Shanghai Institute of Microsystem and Information Technology of the Chinese Academy of Sciences, improved the teleportation rate to 7.1 qubits per second for the first time based on “Qubits per second.”
This presents a new record for a quantum teleportation system in a metropolitan range.
“Demonstrating high-speed quantum teleportation outside a laboratory involves a whole set of challenges. This experiment shows how these challenges can be overcome, and therefore it establishes an important milestone towards the future quantum internet,” said Prof. Qiang Zhou, who is the corresponding author of this work.
The main experimental challenge in a real-world quantum teleportation system is to perform Bell state measurement (BSM). To ensure successful quantum teleportation and improve BSM efficiency, Alice’s and Bob’s photons must be indistinguishable from Charlie’s location after long-distance transmission through the fiber. The team has developed a perfect running feedback system, which realizes the rapid stabilization of the difference in the path length and polarization of the photons.
At the same time, the team used a piece of fiber-pigtailed periodically poled lithium niobate waveguide to generate photon pairs. Based on this, a high-quality quantum entangled light source with a 500 MHz repetition rate was developed for the teleportation system.
Such a high-speed quantum teleportation based on quantum optics requires the most sensitive photon sensors to collect as many events as possible. The team led by Prof. Lixing You, together with partners at Photon Technology Co., LTD, provided high-performance superconducting nanowire single-photon detectors for the experiment. Benefiting from detectors with excellent efficiency and almost no noise, high-efficiency BSM and quantum state analysis are achieved.
The team used quantum state tomography and the decoy state method to calculate the teleportation fidelity, which exceeded the classical limit (66.7%), proving that high-speed metropolitan quantum teleportation had been achieved.
UESTC’s “No. 1 Metropolitan Quantum Internet” is expected to create a “high-speed, high-fidelity, multi-user, long-distance” quantum internet infrastructure in the future by combining integrated quantum light sources, quantum repeaters, and quantum information nodes. The team also predicts that this infrastructure will further promote the practical application of the quantum internet.
More information:
Shen et al, Hertz-rate metropolitan quantum teleportation, Light: Science and Applications (2023). DOI: 10.1038/s41377-023-01158-7
Awarded by the Chinese Academy of Sciences
Citation: Team boosts metropolitan quantum teleportation to hertz rate (2023, July 24) retrieved July 24, 2023 from https://phys.org/news/2023-07-team-boosts-metropolitan-quantum-teleportation.html
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