Quantum Data Centers: Why Entanglement Changes Everything

TL;DR

The paper analyzes quantum networking as a route to scalable distributed quantum computing, arguing that Quantum Data Centers are the viable mid-term architecture. It highlights entanglement-enabled communications, transduction challenges, and the need for orchestrated entanglement generation/distribution to overcome decoherence and no-cloning constraints. A central theme is the Quantum Local Area Network (QLAN) with an orchestrator that uses graph states and LOCC to synthesize artificial topologies, enabling dynamic connectivity beyond physical links. It also outlines the path toward Quantum Hubs by interconnecting QLANs and discusses open issues, including entanglement routing, classical overhead, and compiler-network co-design.

Abstract

The Quantum Internet is key for distributed quantum computing, by interconnecting multiple quantum processors into a virtual quantum computation system. This allows to scale the number of qubits, by overcoming the inherent limitations of noisy-intermediate-scale quantum (NISQ) devices. Thus, the Quantum Internet is the foundation for large-scale, fault-tolerant quantum computation. Among the distributed architectures, Quantum Data Centers emerge as the most viable in the medium-term, since they integrate multiple quantum processors within a localized network infrastructure, by allowing modular design of quantum networking. We analyze the physical and topological constraints of Quantum Data Centers, by emphasizing the role of entanglement orchestrators in dynamically reconfiguring network topologies through local operations. We examine the major hardware challenge of quantum transduction, essential for interfacing heterogeneous quantum systems. Furthermore, we explore how interconnecting multiple Quantum Data Centers could enable large-scale quantum networks. We discuss the topological constraints of such a scaling and identify open challenges, including entanglement routing and synchronization. The carried analysis positions Quantum Data Centers as both a practical implementation platform and strategic framework for the future Quantum Internet.

Figures (9)

• Figure 1: High-level representation of the Distributed Quantum Computing. A crucial in-the-middle component is the compiler, an entity responsible of translating and hardware-agnostic description of the algorithm into a partitioned and fitted version to be executed over the set of individual quantum processors CuoCalKrs-21FerCacAmo-21. As represented in the lowest part of the figure, the set of quantum processing units act as a virtual quantum processor thanks to the interplay of several entities comprising the network infrastructure, represented as quantum communication channels and classical channels, quantum processors and classical processors. Remarkably, the distributed landscape is enabled though three main entanglement-based functional blocks: entanglement generation, entanglement distribution and entanglement utilization.
• Figure 2: Representation of the Distributed Quantum Computing Archetypes. The x-axis denotes the scale of the interconnected processing entities, the y-axis represents the grade of network complexity for the interconnection of the processing entities, the color-bar denotes the grade of heterogeneity required.
• Figure 3: Schematic representation of the role of a quantum transducer as an interface between superconducting nodes and optical network.
• Figure 4: Different transducer-based archetypes for interconnecting superconducting processors. Qubits and ebits at microwave (optical) frequency are depicted in blu (red).
• Figure 5: Probability of EPR distribution $p_e$ in DQT on ebits and in EGT. The superscripts $^s$ and $^d$ indicates that the conversion efficiency refers to the source or destination, respectively.