China News Agency, Hefei, November 18th (Reporter Wu Lan) The reporter learned from the University of Science and Technology of China on the 18th that the team of Academician Guo Guangcan of the school has made important progress in the field of solid-state quantum storage-realizing on-demand quantum storage in the communication band. It is an important step to build a large-scale optical fiber quantum network.
According to reports, this important progress was made by the research team of Li Chuanfeng and Zhou Zongquan.
The achievement was recently published in the internationally renowned academic journal Physical Review Letters.
Quantum memory is the core device of quantum network. By reading entangled photons on demand, the exponential loss in long-distance optical fiber transmission can be reduced to polynomial loss.
In order to use the existing optical fiber network to build a quantum network, the quantum memory should work in the communication band.
However, the readout time of the existing quantum memory in the communication band is preset before the photon is written, and it is impossible to realize on-demand readout.
Rare earth erbium ions are important candidate materials for the realization of communication band quantum memory.
The research team used a series of technical means to control the coherent evolution of erbium ions in the waveguide in real time, and by polarizing the electron spin of erbium ions, the storage efficiency of photons was increased to 10.9%, which is higher than the previously reported integrated communication band quantum Storage gets a 5x boost.
The fidelity of the on-demand quantum storage regulated by the electric field reaches 98.3%, far exceeding the classical limit considering the storage efficiency and photon statistics.
This achievement realizes on-demand quantum storage in the communication band based on erbium ions, and this optical fiber integrated device can be directly connected to the existing optical fiber network.
The reviewer commented that: "Compared with previous work, this work has made important progress, especially the direct bonding of the optical fiber to the optical waveguide, which supports stable operation in a low temperature environment." (End)