Researchers at the University of Science and Technology of China, led by Academician Guo Guangcan, have made significant progress in quantum teleportation research. Collaborating with the theoretical research group at the University of Turku in Finland, the team, including Li Chuanfeng and Liu Zhaodi, successfully overcame environmental noise using multipartite entanglement, achieving high-fidelity quantum teleportation. Their achievement was published in Science Advances on May 1.
Quantum teleportation is a crucial protocol in quantum communication that allows remote transmission of unknown quantum states using quantum entanglement. Due to the fragility of quantum entanglement, quantum teleportation is susceptible to noise interference. Overcoming environmental noise to achieve high-fidelity quantum teleportation is a pressing challenge.
Previously, to address the decoherence issue in open quantum systems in noisy environments, the research team developed a set of methods for complete control of phase decoherence quantum simulators based on clever optical design and programmable spatial light modulators. They successfully implemented noise-resistant quantum teleportation based on nonlocal memory effects. However, nonlocal memory effects require stringent quantum resources like environmental entanglement, which are generally hard to satisfy.
Building on their previous work, in this study, the research team designed and implemented a more universal approach to overcome environmental noise in quantum teleportation.
The researchers first demonstrated that specific phase modulation of the environment of a single quantum system can completely reverse phase decoherence in the evolution of open quantum systems, a method extendable to arbitrary multipartite systems. Using photon polarization as the quantum system and photon frequency as the noise environment, they conducted experiments. By loading specific phase modulation in the environment based on a fully controllable phase decoherence quantum simulator, they prepared initial entangled states of photon pairs in polarization-frequency mixtures, distributing the photons to users Alice and Bob. Alice evolved the decoherence, performed Bell measurements on the quantum state to be transmitted, and then Bob evolved the decoherence. Finally, through classical communication and corresponding unitary operations on the obtained qubits, they achieved the transmitted quantum state with a fidelity close to 90%. As the polarization states of the photon pairs never violated Bell inequalities throughout the process, this experiment realized quantum teleportation based on hidden quantum nonlocality.
The researchers note that this achievement offers a new method to overcome environmental noise distinct from dynamical decoupling and decoherence-free subspaces, with significant implications for a deeper understanding of quantum nonlocality.
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