Photonic Quantum Computing: An Overview

Hamza Hasnaoui, Leonardo Limongi, Taira Giordani +5 more

Under the label of optical quantum computing, there are a variety of protocols and experiments that use the quantum properties of light to achieve a computational advantage over classical computing machines. In this review, we describe some of the main implementations, which differ in the type of encoding and in how the computation is performed, whether using gates or cluster states. For each protocol, we describe advantages and challenges with an overview of the experimental results obtained, summarized in tables. Because of the great relevance achieved in this field, there is a section dedicated to non-universal quantum computation with photons, where boson sampling, variational quantum eigensolvers, and quantum machine learning applications are described. The aim is to give the reader the broadest overview of the applications where photons and their quantum properties play a key role in computation.

Steven P. Hotaling, Andrew R. Pirich

M. AbuGhanem

In the pursuit of scalable and fault-tolerant quantum computing architectures, photonic-based quantum computers have emerged as a leading frontier. This article provides a comprehensive overview of advancements in photonic quantum computing, developed by leading industry players, examining current performance, architectural designs, and strategies for developing large-scale, fault-tolerant photonic quantum computers. It also highlights recent groundbreaking experiments that leverage the unique advantages of photonic technologies, underscoring their transformative potential. This review captures a pivotal moment of photonic quantum computing in the noisy intermediate-scale quantum (NISQ) era, offering insights into how photonic quantum computers might reshape the future of quantum computing.

Steven P. Hotaling, Andrew R. Pirich

Mark G. Thompson

Many efforts around the world are now pursuing the ambitious goal of utility-scale, fault-tolerant quantum computing. Consistent themes are emerging across the field, as teams attempt to scale from existing small systems to the millions of qubits needed for useful applications. Systems partitioning, manufacturability, cooling power, networking, and control electronics are recurring challenges across all qubit technologies. PsiQuantum has pursued a photonic approach, based on qubits implemented using optical photons propagating in lithographically fabricated waveguides. In this talk we will give a broad overview of recent progress, framed against these major scaling challenges. We will describe the basic requirements for photonic quantum computing, the advantages and disadvantages of our approach, and the current state of maturity of the technology.

Chuck Easttom