Scalable implementation of quantum networks and photonic processors require integrated photonic memories with high efficiency, yet current integrated systems have been limited to storage efficiencies below 27.8%. Here, we demonstrate highly efficient integrated quantum memories based on rare-earth-iondoped crystals coupled with impedance-matched microcavities, realized in two novel architectures: 200-micrometer-thin membranes of Eu3+:Y2SiO5 integrated with fiber-based microcavities, and waveguide-based cavities fabricated using femtosecond lasers. Our approach achieves reliable integrated quantum storage with record efficiencies of 80.3(7)% for weak coherent pulses and 69.8(1.6)% for telecom-heralded single photons, alongside the storage of 20 temporal modes with an average efficiency of 51.3(2)%. Moreover, the thin-membrane Eu3+:Y2SiO5 architecture enables spectrally tunable efficient quantum storage via variable strain, providing a flexible interface for quantum networks. By combining high efficiency, large multimode capacity, and tunability, our devices establish a versatile hardware foundation for scalable quantum repeaters and chip-scale photonic processors.
@article{arxiv.2511.05928,
title = {Efficient integrated quantum memory for light},
author = {Ruo-Ran Meng and Pei-Xi Liu and Xiao Liu and Tian-Xiang Zhu and Peng-Jun Liang and Chao Zhang and Zhong-Yang Tang and Hong-Zhe Zhang and Jin-Ming Cui and Ming Jin and Zong-Quan Zhou and Chuan-Feng Li and Guang-Can Guo},
journal= {arXiv preprint arXiv:2511.05928},
year = {2026}
}