Multiplexed storage and real-time manipulation based on a multiple-degree-of-freedom quantum memory

TL;DR

This paper demonstrates a quantum memory capable of storing and manipulating orbital-angular-momentum states along with temporal and spectral modes, advancing the development of scalable quantum networks.

Contribution

It presents the first on-demand storage of orbital-angular-momentum states in a rare-earth-ion doped crystal with high multimode capacity and real-time manipulation capabilities.

Findings

Successful storage of orbital-angular-momentum states at the single-photon level.

High-fidelity quantum mode conversion demonstrated.

Enables arbitrary spectral and temporal manipulations of photonic pulses.

Abstract

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.