Realization of a High-Performance Programmable Photonic Quantum Memory with Over-Thousand Qubit Manipulations

Core Concepts

A high-performance programmable photonic quantum memory is realized, which can simultaneously store 72 optical qubits, support over a thousand consecutive write or read operations in a random access way, and be adapted on-demand for various quantum network functions.

Abstract

The authors report the realization of a high-performance programmable photonic quantum memory that can simultaneously store 72 optical qubits carried by 144 spatially separated atomic ensembles and support up to a thousand consecutive write or read operations in a random access way, two orders of magnitude larger than the previous record. Key highlights: The quantum memory has a coherence time above 0.5 ms for almost all cells, corresponding to the transmission time in a 100 km fiber. The memory can be adapted on-demand for several functions, including quantum queue, stack, and buffer, which closely resemble the counterpart devices for classical information processing. The memory can synchronize and reshuffle 4 entangled pairs of photonic pulses with probabilistic arrival time and arbitrary release order, which is an essential requirement for quantum repeaters and efficient routing in quantum networks. The realization of this multi-purpose programmable quantum memory constitutes a key enabling building block for future large-scale fully-functional quantum networks.

Stats

Quantum memory can simultaneously store 72 optical qubits. The quantum memory supports over a thousand consecutive write or read operations in a random access way. The quantum memory has a coherence time above 0.5 ms for almost all cells. The average fidelity of the retrieved qubits is above 95%. The crosstalk is measured to be about 1%.

Quotes

"Realization of this multi-purpose programmable quantum memory thus constitutes a key enabling building block for future large-scale fully-functional quantum networks." "To achieve a reasonable entangling rate over a metropolitan size of 100 km via the quantum repeater protocol, one has to combine long coherence time, large memory capacity, and high-fidelity operations altogether."

Key Insights Distilled From

Realization of a programmable multi-purpose photonic quantum memory with over-thousand qubit manipulations

by Sheng Zhang,... at arxiv.org 05-01-2024

https://arxiv.org/pdf/2311.10292.pdf

Deeper Inquiries

How can the coherence time and storage efficiency of the quantum memory be further improved to enable long-distance quantum communication and computation

To improve the coherence time and storage efficiency of the quantum memory for long-distance quantum communication and computation, several strategies can be implemented: Material Improvements: Utilizing materials with longer coherence times, such as rare-earth ions in crystals or atomic ensembles with reduced decoherence factors, can enhance the coherence time of the quantum memory. Error Correction Codes: Implementing error correction codes can help mitigate errors and increase the storage efficiency of the quantum memory. By encoding the qubits redundantly, errors can be detected and corrected, leading to improved efficiency. Purification Techniques: Employing purification techniques to remove noise and decoherence from the system can enhance the coherence time of the quantum memory. Purification processes can help maintain the fidelity of stored qubits over longer periods. Optimized Control Techniques: Developing advanced control techniques to minimize external influences and optimize the storage and retrieval processes can improve the coherence time and efficiency of the quantum memory. Precise control over the quantum operations can reduce errors and enhance performance. Hybrid Quantum Memories: Combining different types of quantum memories, such as atomic ensembles and superconducting qubits, in a hybrid architecture can leverage the strengths of each system to achieve longer coherence times and higher storage efficiencies.

What are the potential limitations or challenges in scaling up the capacity and performance of this programmable quantum memory

Scaling up the capacity and performance of the programmable quantum memory may face the following limitations and challenges: Decoherence: As the system size increases, decoherence effects can become more pronounced, limiting the coherence time and efficiency of the quantum memory. Managing and mitigating decoherence at larger scales can be a significant challenge. Interference and Crosstalk: With a larger number of qubits and operations, the potential for interference and crosstalk between qubits in the memory increases. Controlling and minimizing these effects to maintain the integrity of stored quantum information can be challenging. Physical Implementation: Scaling up the quantum memory may require complex and precise physical implementations, such as addressing a larger number of microscopic ensembles or integrating multiple memory units. Ensuring the stability and reliability of such a system can be a technical challenge. Resource Constraints: Increasing the capacity of the quantum memory may require additional resources such as more atoms, lasers, and control systems. Managing these resources efficiently and cost-effectively while maintaining performance can be a limitation. Programming Complexity: As the quantum memory becomes more versatile and programmable for various functions, the complexity of programming and controlling the memory operations may increase. Developing efficient algorithms and software for diverse applications can be a challenge.

How can the programmable quantum memory be integrated with other quantum hardware components, such as quantum processors or quantum sensors, to enable more advanced quantum applications

Integrating the programmable quantum memory with other quantum hardware components can enable advanced quantum applications: Quantum Processors: The programmable quantum memory can be integrated with quantum processors to facilitate quantum computing tasks. By storing and manipulating quantum information in the memory, the quantum processor can access and process the data efficiently. Quantum Sensors: Combining the quantum memory with quantum sensors can enhance the sensitivity and precision of quantum measurements. The memory can store and retrieve quantum states for analysis by the sensors, enabling applications in quantum metrology and sensing. Quantum Repeaters: Integrating the quantum memory into quantum repeater networks can extend the range of quantum communication. By storing and transferring entangled states between distant nodes, the memory can enable long-distance quantum communication with enhanced security and efficiency. Quantum Networks: The programmable quantum memory can serve as a key component in quantum networks, enabling the storage, routing, and synchronization of quantum information between multiple nodes. By integrating with other network elements, the memory can support complex quantum communication protocols and applications.