A selection of the most important recent news, articles, and papers about quantum computing.
News, Articles, and Analyses
Quantum Machines Announces Inaugural Adaptive Quantum Circuits Conference
https://www.prnewswire.com/news-releases/quantum-machines-announces-inaugural-adaptive-quantum-circuits-conference-302217832.html
(Thursday, August 08, 2024) “/PRNewswire/ – Quantum Machines, the leading provider of breakthrough quantum control solutions, today announced the inaugural Adaptive Quantum Circuits (AQC)…”
Quantum’s big numbers game – POLITICO
https://www.politico.com/newsletters/digital-future-daily/2024/08/08/quantums-big-numbers-game-00173281
(Thursday, August 08, 2024) “With potentially billions of dollars of government funding (and profit) at stake in the race to build functional quantum computers, there’s a massive hype machine to match”
Quantum insights: Featured videos by IQC | Institute for Quantum Computing | University of Waterloo
https://uwaterloo.ca/institute-for-quantum-computing/quantum-insights-featured-videos-iqc
“Explore our curated collection of key videos from the Institute for Quantum Computing’s YouTube channel, where groundbreaking research, expert insights, and quantum discoveries come to life. Dive into the world of quantum science and stay informed on the latest developments in the field through these featured highlights.”
Technical Papers, Articles, and Preprints
[2407.12768] A polynomial-time classical algorithm for noisy quantum circuits
https://arxiv.org/abs/2407.12768
Authors: Schuster, Thomas; Yin, Chao; Gao, Xun; Yao, Norman Y.
(Wednesday, July 17, 2024) “We provide a polynomial-time classical algorithm for noisy quantum circuits. The algorithm computes the expectation value of any observable for any circuit, with a small average error over input states drawn from an ensemble (e.g. the computational basis). Our approach is based upon the intuition that noise exponentially damps non-local correlations relative to local correlations. This enables one to classically simulate a noisy quantum circuit by only keeping track of the dynamics of local quantum information. Our algorithm also enables sampling from the output distribution of a circuit in quasi-polynomial time, so long as the distribution anti-concentrates. A number of practical implications are discussed, including a fundamental limit on the efficacy of noise mitigation strategies: any quantum circuit for which error mitigation is efficient must be classically simulable.”
Exponentially tighter bounds on limitations of quantum error mitigation | Nature Physics
https://www.nature.com/articles/s41567-024-02536-7
(Thursday, July 25, 2024) “Error mitigation has helped improve the performance of current quantum computing devices. Now, a mathematical analysis of the technique suggests its benefits may not extend to larger systems.”
[2408.01234] Entanglement Routing in Quantum Networks: A Comprehensive Survey
https://arxiv.org/abs/2408.01234
Authors: Abane, Amar; Cubeddu, Michael; Mai, Van Sy; Battou, Abdella
(Friday, August 02, 2024) “Entanglement routing in near-term quantum networks consists of choosing the optimal sequence of short-range entanglements to combine through swapping operations to establish end-to-end entanglement between two distant nodes. Similar to traditional routing technologies, a quantum routing protocol uses network information to choose the best paths to satisfy a set of end-to-end entanglement requests. However, in addition to network state information, a quantum routing protocol must also take into account the requested entanglement fidelity, the probabilistic nature of swapping operations, and the short lifetime of entangled states. In this work, we formulate a practical entanglement routing problem and analyze and categorize the main approaches to address it, drawing comparisons to, and inspiration from, classical network routing strategies where applicable. We classify and discuss the studied quantum routing schemes into reactive, proactive, opportunistic, and virtual routing”
[2408.04126] Linear-optical quantum computation with arbitrary error-correcting codes
https://arxiv.org/abs/2408.04126
Authors: Walshe, Blayney W.; Baragiola, Ben Q.; Ferretti, Hugo; Gefaell, José; Vasmer, Michael; Weil, Ryohei; Matsuura, Takaya; Jaeken, Thomas; Pantaleoni, Giacomo; Han, Zhihua; Menicucci, Nicolas C.; Tzitrin, Ilan; Alexander, Rafael N.
(Wednesday, August 07, 2024) “High-rate quantum error correcting codes mitigate the imposing scale of fault-tolerant quantum computers but require the efficient generation of non-local many-body entanglement. We provide a linear-optical architecture with these properties, compatible with arbitrary codes and Gottesman-Kitaev-Preskill qubits on generic lattices, and featuring a natural way to leverage physical noise bias. Simulations involving hyperbolic surface codes, promising quantum low-density parity-check codes, reveal a threshold comparable to the 2D surface code at about a ten-fold improvement in encoding rate.”
[2408.04580] Quantum Key Distribution Networks — Key Management: A Survey
https://arxiv.org/abs/2408.04580
Authors: Dervisevic, Emir; Tankovic, Amina; Fazel, Ehsan; Kompella, Ramana; Fazio, Peppino; Voznak, Miroslav; Mehic, Miralem
(Thursday, August 08, 2024) “Secure communication makes the widespread use of telecommunication networks and services possible. With the constant progress of computing and mathematics, new cryptographic methods are being diligently developed. Quantum Key Distribution (QKD) is a promising technology that provides an Information-Theoretically Secure (ITS) solution to the secret-key agreement problem between two remote parties. QKD networks based on trusted repeaters are built to provide service to a larger number of parties at arbitrary distances. They function as an add-on technology to traditional networks, generating, managing, distributing, and supplying ITS cryptographic keys. Since key resources are limited, integrating QKD network services into critical infrastructures necessitates effective key management. As a result, this paper provides a comprehensive review of QKD network key management approaches. They are analyzed to facilitate the identification of potential strategies and accelerate the future development of QKD networks.”
