Quantum Entanglement Among Multiple Memories for Continuous Variables

Abstract

AbstractQuantum network is constituted by quantum channels and quantum nodes. The interaction between non‐classical optical modes and quantum nodes, as well as quantum entanglement among multiple distant quantum nodes are the building blocks of quantum network, which enable to achieve a plethora of quantum information protocols, such as distributed quantum computation, quantum state transfer across quantum nodes, and quantum clock network. On one hand, the multipartite non‐classical states of optical modes, which can directly interact with atomic ensembles, are required for the practical applications of quantum network. On the other hand, a crucial goal of quantum network is to unconditionally generate and on‐demand store and retrieve multipartite entangled states in atomic ensembles. This paper presents an up‐to‐date review on recent developments in these areas: multipartite continuous‐variable polarization entangled optical modes have been created by transforming quantum state from quadrature into polarization components; and a scalable quantum network with deterministic entanglement among multiple quantum memories has been constructed by transferring spatially separated entangled optical modes into atomic ensembles.