Review of Distributed Quantum Computing. From single QPU to High Performance Quantum Computing

TL;DR

This survey maps the state of distributed quantum computing across physical, networking, development, and application layers, highlighting teleportation-based primitives and entanglement as the backbone of nonlocal quantum computation. It reviews architectures for entanglement distribution, including transducers, memories, repeaters, and routers, and details three core distribution strategies—circuit distribution, circuit cutting, and embarrassingly parallel—along with their respective compilation challenges. The authors synthesize current compiler efforts (and the lack thereof) and introduce distributed IRs like InQuIR and NetQASM, framing the need for multi-layered toolchains capable of leveraging modular quantum hardware. They further outline applications that leverage these distributions and circuit knitting, arguing that near-term progress will hinge on hybrid approaches, optimized entanglement management, and programmable quantum networks to bridge disparate quantum devices into scalable quantum-centric HPC ecosystems.

Abstract

The emerging field of quantum computing has shown it might change how we process information by using the unique principles of quantum mechanics. As researchers continue to push the boundaries of quantum technologies to unprecedented levels, distributed quantum computing raises as an obvious path to explore with the aim of boosting the computational power of current quantum systems. This paper presents a comprehensive survey of the current state of the art in the distributed quantum computing field, exploring its foundational principles, landscape of achievements, challenges, and promising directions for further research. From quantum communication protocols to entanglement-based distributed algorithms, each aspect contributes to the mosaic of distributed quantum computing, making it an attractive approach to address the limitations of classical computing. Our objective is to provide an exhaustive overview for experienced researchers and field newcomers.

Figures (13)

• Figure 1: Layered model for distributed quantum computing.
• Figure 2: Sketch of quantum communication protocols: (a) Quantum-state teleportation (teledata), (b) entanglement swapping, and (c) quantum-gate teleportation (telegate). BSM: Bell-state measurement. CM: controlled operation and projective measurement.
• Figure 3: Examples of teledata and telegate circuits for the application of CZs gates over $|t_1\rangle$ and $|t_2\rangle$ with the remote state $|a\rangle$ as control. (a) The state $|a\rangle$ in QPU1 is teleported to the first qubit of QPU2 (b) Cat-entangler and cat-disentangler primitives Yimsiriwattana2004Generalized are used to implement the remote control.
• Figure 4: Diagram representing photonic entanglement swapping by Bell-state measurement. BS: beam splitter; PBS: polarizing beam splitter; h1, h2, v1, v2: single photon detectors.
• Figure 5: Quantum networking devices and interconnects for distributed quantum computing (see main text for details).