Quantum memory devices with high storage efficiency and bandwidth are essential elements for future quantum networks. Solid-state quantum memories can provide broadband storage, but they primarily suffer from low storage efficiency. We use passive optimization and algorithmic optimization techniques to demonstrate nearly a sixfold enhancement in quantum memory efficiency. In this regime, we demonstrate coherent and single-photon-level storage with a high signal-to-noise ratio. The optimization technique presented here can be applied to most solid-state quantum memories to significantly improve the storage efficiency without compromising the memory bandwidth. Published by the American Physical Society2024
more »
« less
Ultra-broadband On-Resonance Quantum Storage in Hot Atomic Barium Vapor
Quantum memories are of critical importance to the scalability of quantum information processing and quantum technologies in communication, measurement, and computation. Here we present numerical simulation of the storage of ultra-broadband photons in hot atomic barium vapor, which allows for quantum memory operation at telecom wavelengths. We numerically calculate the optimal control field profiles for the storage process both through direct Nedler-Mead simplex search and by singular value decomposition of the storage kernel, where the latter guarantees optimality. We provide a physical interpretation of our numerical results related in part to recent work on Autler-Townes-Splitting (ATS) based quantum memory, and show saturation of the protocol-independent bound on storage efficiency imposed by the optical depth for pulses of duration 200 fs to 17.5 ps. In conclusion we provide an outlook for implementing these results experimentally.
more »
« less
- PAR ID:
- 10208645
- Date Published:
- Journal Name:
- 51st Annual Meeting of the APS Division of Atomic, Molecular and Optical Physics
- Volume:
- 65
- Issue:
- 4
- Page Range / eLocation ID:
- G02.00001
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Efficient storage of telecom-band quantum optical information represents a crucial milestone for establishing distributed quantum optical networks. Erbium ions in crystalline hosts provide a promising platform for telecom quantum memories; however, their practical applications have been hindered by demanding operational conditions, such as ultra-high magnetic fields and ultra-low temperatures. In this work, we demonstrate the storage of telecom photonic qubits encoded in polarization, frequency, and time-bin bases. Using the atomic frequency comb protocol in an Er3+-doped crystal, we developed a memory initialization scheme that improves storage efficiency by over an order of magnitude. The observed results were made possible by the deliberate selection of the pumping sequence and the minimization of lattice interactions, to the extent possible without the use of dilution refrigerators or superconducting magnets.more » « less
-
Optical photons are powerful carriers of quantum information, which can be delivered in free space by satellites or in fibers on the ground over long distances. Entanglement of quantum states over long distances can empower quantum computing, quantum communications, and quantum sensing. Quantum optical memories are devices designed to store quantum information in the form of stationary excitations, such as atomic coherence, and are capable of coherently mapping these excitations to flying qubits. Quantum memories can effectively store and manipulate quantum states, making them indispensable elements in future long-distance quantum networks. Over the past two decades, quantum optical memories with high fidelities, high efficiencies, long storage times, and promising multiplexing capabilities have been developed, especially at the single-photon level. In this review, we introduce the working principles of commonly used quantum memory protocols and summarize the recent advances in quantum memory demonstrations. We also offer a vision for future quantum optical memory devices that may enable entanglement distribution over long distances.more » « less
-
Abstract A key challenge in realizing practical quantum networks for long-distance quantum communication involves robust entanglement between quantum memory nodes connected by fibre optical infrastructure1–3. Here we demonstrate a two-node quantum network composed of multi-qubit registers based on silicon-vacancy (SiV) centres in nanophotonic diamond cavities integrated with a telecommunication fibre network. Remote entanglement is generated by the cavity-enhanced interactions between the electron spin qubits of the SiVs and optical photons. Serial, heralded spin-photon entangling gate operations with time-bin qubits are used for robust entanglement of separated nodes. Long-lived nuclear spin qubits are used to provide second-long entanglement storage and integrated error detection. By integrating efficient bidirectional quantum frequency conversion of photonic communication qubits to telecommunication frequencies (1,350 nm), we demonstrate the entanglement of two nuclear spin memories through 40 km spools of low-loss fibre and a 35-km long fibre loop deployed in the Boston area urban environment, representing an enabling step towards practical quantum repeaters and large-scale quantum networks.more » « less
-
As in-memory data analytics become increasingly important in a wide range of domains, the ability to develop large-scale and sustainable platforms faces significant challenges related to storage latency and memory size constraints. These challenges can be resolved by adopting new and effective formulations and novel architectures such as software-defined infrastructure. This paper investigates the key issue of data persistency for in-memory processing systems by evaluating persistence methods using different storage and memory devices for Apache Spark and the use of Alluxio. It also proposes and evaluates via simulation a Spark execution model for using disaggregated off- rack memory and non-volatile memory targeting next-generation software-defined infrastructure. Experimental results provide better understanding of behaviors and requirements for improving data persistence in current in-memory systems and provide data points to better understand requirements and design choices for next-generation software-defined infrastructure. The findings indicate that in-memory processing systems can benefit from ongoing software-defined infrastructure implementations; however current frameworks need to be enhanced appropriately to run efficiently at scale.more » « less
An official website of the United States government

