A Lattice-Trapped and Cavity-Enhanced High-Quality Quantum Memory

Quantum memory plays an increasing essential part in many applications of quantum information science. Currently, the intense research and crucial challenge is that integration of a full functional quantum memory with various high-performance properties in a single system. Storage lifetime and retrieval efficiency are the two most important qualities of quantum memory, especially indispensable for quantum repeater and long-distance quantum communication. Here based on techniques of magic optical lattice trap and ring cavity enhancement, we experimentally achieved a high-quality cold atom quantum memory. The initial intrinsic retrieval efficiency is up to 77(5)\%, with an $\rm{e^{-1}}$-storage lifetime about 0.25 sec for the first time. Such high effective and long-lived quantum memory should be significantly important for quantum communication and cryptography, and would truly stimulate a first practical demonstration of long distance quantum repeaters in the near future.