Prof. Luming Duan’s research group at CQI, Tsinghua University, has made a significant advance in quantum information field by reporting the experimental realization of quantum memory with 225 individually accessible memory cells. The research, entitled with Experimental Realization of a Multiplexed Quantum Memory with 225 Individually Accessible Memory Cells, was recently published in Nature Communications.

Multiplexed quantum memory is a key component for realization of long-distance quantum communication and quantum network. Quantum repeater is required in long-distance quantum communication to overcome the exponential decay issue in the optical transmission channel. The seminal DLCZ (Duan-Lukin-Cirac-Zoller) scheme, proposed by Prof. Duan and his collaborators in 2001, combined atomic ensemble quantum memory and single photon channel, to overcome the exponential photon decay in the transmission channel. Implementation of quantum repeaters along the DLCZ scheme has raised world-wide interest with significant experimental progress. The need of multiplexed quantum memory with many independently accessible memory cells is identified as one of the key requirements for experimental realization of quantum repeaters.

By adopting 2D array of quantum memory cells, Prof. Duan’s group greatly improved the capacity of quantum memory and increased the number of memory cells to 225, which is nearly 20 times more than the former world record  on similar scenarios. The reviewer recommended this work “represents a significant milestone in the development of quantum memory technology for real applications.”

The first author of this paper is Yunfei Pu, PhD candidate of CQI. Prof. Duan is the corresponding author. Other authors include CQI PhD candidates Nan Jiang, Haoxiang Yang, Wei Chang and Chang Li. The research was funded by the Ministry of Education of China and the Tsinghua-QTEC Joint Lab on quantum networks. 

(By Shuai Sun)