[Paper Review] Data centers with quantum random access memory and quantum networks

Junyu Liu, Connor T. Hann+1 more|arXiv (Cornell University)|Jul 28, 2022

Quantum Information and Cryptography4 citations

TL;DR

This paper proposes the Quantum Data Center (QDC), an integrated architecture combining Quantum Random Access Memory (QRAM) and quantum networks to enable efficient, private, and scalable processing of quantum data. The QDC supports advanced applications in fault-tolerant quantum computing, multi-party private quantum communication, and distributed quantum sensing through optimized quantum data access and coherent control, demonstrating significant advantages over classical or isolated quantum approaches.

ABSTRACT

In this paper, we propose the Quantum Data Center (QDC), an architecture combining Quantum Random Access Memory (QRAM) and quantum networks. We give a precise definition of QDC, and discuss its possible realizations and extensions. We discuss applications of QDC in quantum computation, quantum communication, and quantum sensing, with a primary focus on QDC for $T$-gate resources, QDC for multi-party private quantum communication, and QDC for distributed sensing through data compression. We show that QDC will provide efficient, private, and fast services as a future version of data centers.

Motivation & Objective

• To design a unified quantum infrastructure that efficiently manages classical and quantum data across distributed systems.
• To address the challenge of interfacing classical data with quantum processors through a general-purpose, high-speed access mechanism.
• To enable private and secure quantum communication and sensing by integrating QRAM with quantum networks.
• To reduce the complexity of designing optimal quantum circuits for sensing and computation by offloading unitary synthesis to a centralized quantum resource.

Proposed method

• The QDC is defined as a quantum or classical database equipped with QRAM and connected to a quantum network, enabling superposition access to stored data.
• QRAM allows input of a superposition of addresses, returning an entangled state of addresses and corresponding data, enabling parallel data retrieval.
• The architecture supports three core applications: fault-tolerant quantum computation via QRAM as a data-lookup oracle, multi-party private quantum communication combining QPQ and quantum secret sharing, and distributed sensing with quantum data compression.
• For sensing, the QDC designs optimal hybrid protocols (ξ-hybrid) that balance coherence and measurement efficiency, reducing circuit design burden.
• Quantum teleportation via the network enables remote application of unitaries (e.g., Vℓ) on qubits sent from users to the QDC.
• The QDC can perform Schumacher coding in polylogarithmic time using quantum sorting networks, enabling high-bandwidth data compression.

Experimental results

Research questions

• RQ1 How can a centralized quantum infrastructure efficiently and privately manage access to distributed quantum and classical data?
• RQ2 What architectural components are necessary to realize a scalable, fault-tolerant quantum data center?
• RQ3 Can QDCs outperform classical or isolated quantum systems in private quantum communication and sensing tasks?
• RQ4 How can the QDC reduce the complexity of designing optimal quantum circuits for channel discrimination and data processing?
• RQ5 What role does QRAM play in enabling coherent, high-precision quantum sensing protocols?

Key findings

• The QDC enables efficient, private, and fast services for quantum computation, communication, and sensing by integrating QRAM and quantum networks.
• QRAM allows superposition access to classical or quantum data, enabling parallel data retrieval with minimal overhead.
• The QDC supports multi-party private quantum communication by combining Quantum Private Query (QPQ) and Quantum Secret Sharing, ensuring data confidentiality.
• For distributed sensing, the QDC can implement optimal ξ-hybrid protocols that outperform purely incoherent or coherent schemes under noise.
• The QDC reduces the circuit design burden by offloading unitary synthesis to a centralized resource, enabling scalable implementation of complex quantum protocols.
• Schumacher coding can be implemented in polylogarithmic time using quantum sorting networks within the QDC, significantly improving detector bandwidth.