Paper A (simple) classical algorithm for estimating Betti numbers Simon Apers, Sander Gribling, Sayantan Sen, and Dániel Szabó, Quantum 7, 1202 (2023). We describe a simple algorithm for estimating the $k$-th normalized Betti number of a simplicial complex over $n$ elements using the path integral Monte Carlo method. For a general simplicial co…
Paper Improving the performance of twin-field quantum key distribution with advantage distillation technology Hong-Wei Li, Rui-Qiang Wang, Chun-Mei Zhang, and Qing-Yu Cai, Quantum 7, 1201 (2023). In this work, we apply the advantage distillation method to improve the performance of a practical twin-field quantum key distribution system under collective attack. Compared with the previ…
Paper Entanglement dynamics in U(1) symmetric hybrid quantum automaton circuits Yiqiu Han and Xiao Chen, Quantum 7, 1200 (2023). We study the entanglement dynamics of quantum automaton (QA) circuits in the presence of U(1) symmetry. We find that the second Rényi entropy grows diffusively with a logarithmic correction…
Paper Upper bounds on key rates in device-independent quantum key distribution based on convex-combination attacks Karol Łukanowski, Maria Balanzó-Juandó, Máté Farkas, Antonio Acín, and Jan Kołodyński, Quantum 7, 1199 (2023). The device-independent framework constitutes the most pragmatic approach to quantum protocols that does not put any trust in their implementations. It requires all claims, about e.g. securit…
Paper High-performance repetition cat code using fast noisy operations Francois-Marie Le Régent, Camille Berdou, Zaki Leghtas, Jérémie Guillaud, and Mazyar Mirrahimi, Quantum 7, 1198 (2023). Bosonic cat qubits stabilized by two-photon driven dissipation benefit from exponential suppression of bit-flip errors and an extensive set of gates preserving this protection. These propert…
Paper Fitting quantum noise models to tomography data Emilio Onorati, Tamara Kohler, and Toby S. Cubitt, Quantum 7, 1197 (2023). The presence of noise is currently one of the main obstacles to achieving large-scale quantum computation. Strategies to characterise and understand noise processes in quantum hardware are a…
Paper Entanglement-efficient bipartite-distributed quantum computing Jun-Yi Wu, Kosuke Matsui, Tim Forrer, Akihito Soeda, Pablo Andrés-Martínez, Daniel Mills, Luciana Henaut, and Mio Murao, Quantum 7, 1196 (2023). In noisy intermediate-scale quantum computing, the limited scalability of a single quantum processing unit (QPU) can be extended through distributed quantum computing (DQC), in which one can…
Paper Recovery With Incomplete Knowledge: Fundamental Bounds on Real-Time Quantum Memories Arshag Danageozian, Quantum 7, 1195 (2023). The recovery of fragile quantum states from decoherence is the basis of building a quantum memory, with applications ranging from quantum communications to quantum computing. Many recovery t…
Paper Understanding the interplay of entanglement and nonlocality: motivating and developing a new branch of entanglement theory David Schmid, Thomas C. Fraser, Ravi Kunjwal, Ana Belen Sainz, Elie Wolfe, and Robert W. Spekkens, Quantum 7, 1194 (2023). A standard approach to quantifying resources is to determine which operations on the resources are freely available, and to deduce the partial order over resources that is induced by the rel…
Paper The quartic Blochnium: an anharmonic quasicharge superconducting qubit Luca Chirolli, Matteo Carrega, and Francesco Giazotto, Quantum 7, 1193 (2023). The quasicharge superconducting qubit realizes the dual of the transmon and shows strong robustness to flux and charge fluctuations thanks to a very large inductance closed on a Josephson ju…
Paper Differentiable matrix product states for simulating variational quantum computational chemistry Chu Guo, Yi Fan, Zhiqian Xu, and Honghui Shang, Quantum 7, 1192 (2023). Quantum Computing is believed to be the ultimate solution for quantum chemistry problems. Before the advent of large-scale, fully fault-tolerant quantum computers, the variational quantum ei…
Perspective Towards real-world implementations of quantum machine learning Junyu Liu, Quantum Views 7, 77 (2023). Quantum machine learning, which involves algorithms akin to machine learning operating on quantum devices, is anticipated to be a flagship application for quantum technologies. In the short…
Paper Quantum Deep Hedging El Amine Cherrat, Snehal Raj, Iordanis Kerenidis, Abhishek Shekhar, Ben Wood, Jon Dee, Shouvanik Chakrabarti, Richard Chen, Dylan Herman, Shaohan Hu, Pierre Minssen, Ruslan Shaydulin, Yue Sun, Romina Yalovetzky, and Marco Pistoia, Quantum 7, 1191 (2023). Quantum machine learning has the potential for a transformative impact across industry sectors and in particular in finance. In our work we look at the problem of hedging where deep reinforc…
Paper Energy measurements remain thermometrically optimal beyond weak coupling Jonas Glatthard, Karen V. Hovhannisyan, Martí Perarnau-Llobet, Luis A. Correa, and Harry J. D. Miller, Quantum 7, 1190 (2023). We develop a general perturbative theory of finite-coupling quantum thermometry up to second order in probe-sample interaction. By assumption, the probe and sample are in thermal equilibrium…
Paper Efficient classical algorithms for simulating symmetric quantum systems Eric R. Anschuetz, Andreas Bauer, Bobak T. Kiani, and Seth Lloyd, Quantum 7, 1189 (2023). In light of recently proposed quantum algorithms that incorporate symmetries in the hope of quantum advantage, we show that with symmetries that are restrictive enough, classical algorithms…
Paper Variational Quantum Linear Solver Carlos Bravo-Prieto, Ryan LaRose, M. Cerezo, Yigit Subasi, Lukasz Cincio, and Patrick J. Coles, Quantum 7, 1188 (2023). Previously proposed quantum algorithms for solving linear systems of equations cannot be implemented in the near term due to the required circuit depth. Here, we propose a hybrid quantum-cla…
