Abstract:
Quantum memories are indispensable for quantum communications. A quantum memory is able to realize the storage and retrieval of a quantum state, such as a single photon, entanglement,or a squeezed state, on demand. The ability to store multimode signals is an important property for a quantum memory. It is shown that a high spatial multimode capacity can significantly reduce the time required to store a quantum state, therefore the storage of spatial multimode signals has attracted wide attention worldwide and much progress has been achieved in recent years.In this paper we briefly introduce the main benchmarks for quantum memories and review the current state-of-the-art, in particular the latest experimental achievements in the storage of quantum images.