The faithful storage and coherent manipulation of quantum states with matter-systems enable the construction of large-scale quantum networks based on quantum repeater. To achieve useful communication rates, highly multimode quantum memories will be required to construct a multiplexed quantum repeater. Here, we present the first demonstration of the on-demand storage of orbital-angular-momentum states with weak coherent pulses at the single-photon-level in a rare-earth-ion doped crystal. Through the combination of this spatial degree-of-freedom with temporal and spectral degrees of freedom, we create a multiple-degree-of-freedom memory with high multimode capacity. This device can serve as a quantum mode converter with high fidelity, which is the fundamental requirements for the construction of a multiplexed quantum repeater. This device further enables essentially arbitrary spectral and temporal manipulations of spatial-qutrit-encoded photonic pulses in real-time. Therefore, the developed quantum memory can serve as a building block for scalable photonic quantum information processing architectures.
@article{arxiv.1808.01565,
title = {Multiplexed storage and real-time manipulation based on a multiple-degree-of-freedom quantum memory},
author = {Tian-Shu Yang and Zong-Quan Zhou and Yi-Lin Hua and Xiao Liu and Zong-Feng Li and Pei-Yun Li and Yu Ma and Chao Liu and Peng-Jun Liang and Xue Li and Yi-Xin Xiao and Jun Hu and Chuan-Feng Li and Guang-Can Guo},
journal= {arXiv preprint arXiv:1808.01565},
year = {2018}
}