Mattia Walschaers,

Quantum 7, 1038 (2023).

Quantum correlations and Wigner negativity are two important signatures of nonclassicality in continuous-variable quantum systems. In this work, we investigate how both are intertwined in th…

Daniel Bultrini, Max Hunter Gordon, Piotr Czarnik, Andrew Arrasmith, M. Cerezo, Patrick J. Coles, and Lukasz Cincio,

Quantum 7, 1034 (2023).

Error mitigation is an essential component of achieving a practical quantum advantage in the near term, and a number of different approaches have been proposed. In this work, we recognize th…

M. Hamed Mohammady, Takayuki Miyadera, and Leon Loveridge,

Quantum 7, 1033 (2023).

Measurement error and disturbance, in the presence of conservation laws, are analysed in general operational terms. We provide novel quantitative bounds demonstrating necessary conditions un…

Haoya Li, Hongkang Ni, and Lexing Ying,

Quantum 7, 1031 (2023).

Block encoding lies at the core of many existing quantum algorithms. Meanwhile, efficient and explicit block encodings of dense operators are commonly acknowledged as a challenging problem.…

Yizhou Liu, Weijie J. Su, and Tongyang Li,

Quantum 7, 1030 (2023).

Classical algorithms are often not effective for solving nonconvex optimization problems where local minima are separated by high barriers. In this paper, we explore possible quantum speedup…

Ludmila Viotti, Ana Laura Gramajo, Paula I. Villar, Fernando C. Lombardo, and Rosario Fazio,

Quantum 7, 1029 (2023).

A monitored quantum system undergoing a cyclic evolution of the parameters governing its Hamiltonian accumulates a geometric phase that depends on the quantum trajectory followed by the syst…

Neil Dowling, Pedro Figueroa-Romero, Felix A. Pollock, Philipp Strasberg, and Kavan Modi,

Quantum 7, 1027 (2023).

Equilibrium statistical mechanics provides powerful tools to understand physics at the macroscale. Yet, the question remains how this can be justified based on a microscopic quantum descript…

Ahmed A. Akhtar, Hong-Ye Hu, and Yi-Zhuang You,

Quantum 7, 1026 (2023).

Classical shadow tomography is a powerful randomized measurement protocol for predicting many properties of a quantum state with few measurements. Two classical shadow protocols have been ex…

Jasminder S. Sidhu, Michael S. Bullock, Saikat Guha, and Cosmo Lupo,

Quantum 7, 1025 (2023).

Coherent states of the quantum electromagnetic field, the quantum description of ideal laser light, are prime candidates as information carriers for optical communications. A large body of l…

Marco Ballarin, Stefano Mangini, Simone Montangero, Chiara Macchiavello, and Riccardo Mengoni,

Quantum 7, 1023 (2023).

Quantum Neural Networks (QNN) are considered a candidate for achieving quantum advantage in the Noisy Intermediate Scale Quantum computer (NISQ) era. Several QNN architectures have been prop…

Soumik Bandyopadhyay, Philipp Uhrich, Alessio Paviglianiti, and Philipp Hauke,

Quantum 7, 1022 (2023).

Equilibrium quantum many-body systems in the vicinity of phase transitions generically manifest universality. In contrast, limited knowledge has been gained on possible universal characteris…

Zacharie Van Herstraeten, Michael G. Jabbour, and Nicolas J. Cerf,

Quantum 7, 1021 (2023).

We explore the role of majorization theory in quantum phase space. To this purpose, we restrict ourselves to quantum states with positive Wigner functions and show that the continuous versio…

Pavel Kos and Georgios Styliaris,

Quantum 7, 1020 (2023).

Exact solutions in interacting many-body systems are scarce but extremely valuable since they provide insights into the dynamics. Dual-unitary models are examples in one spatial dimension wh…

Mateus Araújo, Marcus Huber, Miguel Navascués, Matej Pivoluska, and Armin Tavakoli,

Quantum 7, 1019 (2023).

Computing the key rate in quantum key distribution (QKD) protocols is a long standing challenge. Analytical methods are limited to a handful of protocols with highly symmetric measurement ba…

William Kirby, Mario Motta, and Antonio Mezzacapo,

Quantum 7, 1018 (2023).

We present an algorithm that uses block encoding on a quantum computer to exactly construct a Krylov space, which can be used as the basis for the Lanczos method to estimate extremal eigenva…

Joseph T. Iosue, Adam Ehrenberg, Dominik Hangleiter, Abhinav Deshpande, and Alexey V. Gorshkov,

Quantum 7, 1017 (2023).

Bosonic Gaussian states are a special class of quantum states in an infinite dimensional Hilbert space that are relevant to universal continuous-variable quantum computation as well as to ne…

Álvaro Gómez-León, Tomás Ramos, Alejandro González-Tudela, and Diego Porras,

Quantum 7, 1016 (2023).

We study the phenomena of topological amplification in arrays of parametric oscillators. We find two phases of topological amplification, both with directional transport and exponential gain…

Arthur J. Parzygnat and Francesco Buscemi,

Quantum 7, 1013 (2023).

We propose a category-theoretic definition of retrodiction and use it to exhibit a time-reversal symmetry for all quantum channels. We do this by introducing retrodiction families and functo…

Koji Yamaguchi and Hiroyasu Tajima,

Quantum 7, 1012 (2023).

Metric adjusted skew information, induced from quantum Fisher information, is a well-known family of resource measures in the resource theory of asymmetry. However, its asymptotic rates are…

Hamza Fawzi, Omar Fawzi, and Samuel O. Scalet,

Quantum 7, 1011 (2023).

We introduce a classical algorithm to approximate the free energy of local, translation-invariant, one-dimensional quantum systems in the thermodynamic limit of infinite chain size. While th…

Cihan Okay, Aziz Kharoof, and Selman Ipek,

Quantum 7, 1009 (2023).

We introduce a new framework for contextuality based on simplicial sets, combinatorial models of topological spaces that play a prominent role in modern homotopy theory. Our approach extends…

Ankit Kumar, Tanjung Krisnanda, Paramasivan Arumugam, and Tomasz Paterek,

Quantum 7, 1008 (2023).

We describe a complete method for a precise study of gravitational interaction between two nearby quantum masses. Since the displacements of these masses are much smaller than the initial se…

Swarnadeep Majumder, Christopher G. Yale, Titus D. Morris, Daniel S. Lobser, Ashlyn D. Burch, Matthew N. H. Chow, Melissa C. Revelle, Susan M. Clark, and Raphael C. Pooser,

Quantum 7, 1006 (2023).

Quantum computing testbeds exhibit high-fidelity quantum control over small collections of qubits, enabling performance of precise, repeatable operations followed by measurements. Currently,…

Joschka Roffe, Lawrence Z. Cohen, Armanda O. Quintavalle, Daryus Chandra, and Earl T. Campbell,

Quantum 7, 1005 (2023).

Bias-tailoring allows quantum error correction codes to exploit qubit noise asymmetry. Recently, it was shown that a modified form of the surface code, the XZZX code, exhibits considerably i…

Lucas Tendick, Martin Kliesch, Hermann Kampermann, and Dagmar Bruß,

Quantum 7, 1003 (2023).

The advantage that quantum systems provide for certain quantum information processing tasks over their classical counterparts can be quantified within the general framework of resource theor…

Wilfred Salmon, Sergii Strelchuk, and David Arvidsson-Shukur,

Quantum 7, 998 (2023).

Measurements of quantum states form a key component in quantum-information processing. It is therefore an important task to compare measurements and furthermore decide if a measurement strat…

Ryan Shaffer, Hang Ren, Emiliia Dyrenkova, Christopher G. Yale, Daniel S. Lobser, Ashlyn D. Burch, Matthew N. H. Chow, Melissa C. Revelle, Susan M. Clark, and Hartmut Häffner,

Quantum 7, 997 (2023).

Most near-term quantum information processing devices will not be capable of implementing quantum error correction and the associated logical quantum gate set. Instead, quantum circuits will…

Emanuel-Cristian Boghiu, Elie Wolfe, and Alejandro Pozas-Kerstjens,

Quantum 7, 996 (2023).

We introduce Inflation, a Python library for assessing whether an observed probability distribution is compatible with a causal explanation. This is a central problem in both theoretical and…

Kouhei Nakaji, Suguru Endo, Yuichiro Matsuzaki, and Hideaki Hakoshima,

Quantum 7, 995 (2023).

Simulating large quantum systems is the ultimate goal of quantum computing. Variational quantum simulation (VQS) gives us a tool to achieve the goal in near-term devices by distributing the…

Ben Barber, Neil I. Gillespie, and J. M. Taylor,

Quantum 7, 994 (2023).

Rapidly improving gate fidelities for coherent operations mean that errors in state preparation and measurement (SPAM) may become a dominant source of error for fault-tolerant operation of q…

Nikita A. Nemkov, Evgeniy O. Kiktenko, Ilia A. Luchnikov, and Aleksey K. Fedorov,

Quantum 7, 993 (2023).

We consider the problem of the variational quantum circuit synthesis into a gate set consisting of the CNOT gate and arbitrary single-qubit (1q) gates with the primary target being the minim…

Paul Hilaire, Leonid Vidro, Hagai S. Eisenberg, and Sophia E. Economou,

Quantum 7, 992 (2023).

Since linear-optical two-photon gates are inherently probabilistic, measurement-based implementations are particularly well suited for photonic platforms: a large highly-entangled photonic r…

Philip Taranto, Thomas J. Elliott, and Simon Milz,

Quantum 7, 991 (2023).

In classical physics, memoryless dynamics and Markovian statistics are one and the same. This is not true for quantum dynamics, first and foremost because quantum measurements are invasive.…

Xiao Xiao, J. K. Freericks, and A. F. Kemper,

Quantum 7, 987 (2023).

Topological quantum phases of quantum materials are defined through their topological invariants. These topological invariants are quantities that characterize the global geometrical propert…

Ricardo Faleiro, Nikola Paunkovic, and Marko Vojinovic,

Quantum 7, 986 (2023).

This work overviews the single-particle two-way communication protocol recently introduced by del Santo and Dakić (dSD), and analyses it using the process matrix formalism. We give a detaile…

Maxime Tremblay, Guillaume Duclos-Cianci, and Stefanos Kourtis,

Quantum 7, 985 (2023).

We introduce a methodology for generating random multi-qubit stabilizer codes based on solving a constraint satisfaction problem (CSP) on random bipartite graphs. This framework allows us to…

Pascal Baßler, Matthias Zipper, Christopher Cedzich, Markus Heinrich, Patrick H. Huber, Michael Johanning, and Martin Kliesch,

Quantum 7, 984 (2023).

We develop a method to synthesize a class of entangling multi-qubit gates for a quantum computing platform with fixed Ising-type interaction with all-to-all connectivity. The only requiremen…

T. T. Sergeev, A. A. Zyablovsky, E. S. Andrianov, and Yu. E. Lozovik,

Quantum 7, 982 (2023).

Exceptional point (EP) is a spectral singularity in non-Hermitian systems. The passing over the EP leads to a phase transition, which endows the system with unconventional features that find…

Yusen Wu, Bujiao Wu, Jingbo Wang, and Xiao Yuan,

Quantum 7, 981 (2023).

The application of quantum computation to accelerate machine learning algorithms is one of the most promising areas of research in quantum algorithms. In this paper, we explore the power of…

Robert Raussendorf, Cihan Okay, Michael Zurel, and Polina Feldmann,

Quantum 7, 979 (2023).

A web of cohomological facts relates quantum error correction, measurement-based quantum computation, symmetry protected topological order and contextuality. Here we extend this web to quant…

Xuanqiang Zhao, Benchi Zhao, Zihan Xia, and Xin Wang,

Quantum 7, 978 (2023).

Extracting classical information from quantum systems is an essential step of many quantum algorithms. However, this information could be corrupted as the systems are prone to quantum noises…

Oriel Kiss, Michele Grossi, and Alessandro Roggero,

Quantum 7, 977 (2023).

Simulating many-body quantum systems is a promising task for quantum computers. However, the depth of most algorithms, such as product formulas, scales with the number of terms in the Hamilt…

Yanglin Hu, Yingkai Ouyang, and Marco Tomamichel,

Quantum 7, 976 (2023).

Quantum homomorphic encryption, which allows computation by a server directly on encrypted data, is a fundamental primitive out of which more complex quantum cryptography protocols can be bu…

Jacob Bringewatt and Zohreh Davoudi,

Quantum 7, 975 (2023).

Mapping fermionic operators to qubit operators is an essential step for simulating fermionic systems on a quantum computer. We investigate how the choice of such a mapping interacts with the…

Enrique Cervero Martín, Kirill Plekhanov, and Michael Lubasch,

Quantum 7, 974 (2023).

We analyze the barren plateau phenomenon in the variational optimization of quantum circuits inspired by matrix product states (qMPS), tree tensor networks (qTTN), and the multiscale entangl…

Alfred Godley and Madalin Guta,

Quantum 7, 973 (2023).

Continuous-time measurements are instrumental for a multitude of tasks in quantum engineering and quantum control, including the estimation of dynamical parameters of open quantum systems mo…

Peter Groszkowski, Alireza Seif, Jens Koch, and A. A. Clerk,

Quantum 7, 972 (2023).

Driven quantum systems subject to non-Markovian noise are typically difficult to model even if the noise is classical. We present a systematic method based on generalized cumulant expansions…

Anthony N. Ciavarella, Stephan Caspar, Marc Illa, and Martin J. Savage,

Quantum 7, 970 (2023).

An adiabatic state preparation technique, called the adiabatic spiral, is proposed for the Heisenberg model. This technique is suitable for implementation on a number of quantum simulation p…

Cameron Foreman, Sherilyn Wright, Alec Edgington, Mario Berta, and Florian J. Curchod,

Quantum 7, 969 (2023).

We present an end-to-end and practical randomness amplification and privatisation protocol based on Bell tests. This allows the building of device-independent random number generators which…

Simone Roncallo, Krzysztof Sacha, and Lorenzo Maccone,

Quantum 7, 968 (2023).

We compare the proposals that have appeared in the literature to describe a measurement of the time of arrival of a quantum particle at a detector. We show that there are multiple regimes wh…

Jeffrey C. Y. Teo and Yichen Hu,

Quantum 7, 967 (2023).

We present a family of electron-based coupled-wire models of bosonic orbifold topological phases, referred to as twist liquids, in two spatial dimensions. All local fermion degrees of freedo…

Gabriel Matos, Chris N. Self, Zlatko Papić, Konstantinos Meichanetzidis, and Henrik Dreyer,

Quantum 7, 966 (2023).

We study variational quantum algorithms from the perspective of free fermions. By deriving the explicit structure of the associated Lie algebras, we show that the Quantum Approximate Optimiz…

Robin Corgier, Marco Malitesta, Augusto Smerzi, and Luca Pezzè,

Quantum 7, 965 (2023).

Thanks to common-mode noise rejection, differential configurations are crucial for realistic applications of phase and frequency estimation with atom interferometers. Currently, differential…

Philipp Seitz, Ismael Medina, Esther Cruz, Qunsheng Huang, and Christian B. Mendl,

Quantum 7, 964 (2023).

We develop and analyze a method for simulating quantum circuits on classical computers by representing quantum states as rooted tree tensor networks. Our algorithm first determines a suitabl…

Kaoru Mizuta and Keisuke Fujii,

Quantum 7, 962 (2023).

The implementation of time-evolution operators $U(t)$, called Hamiltonian simulation, is one of the most promising usage of quantum computers. For time-independent Hamiltonians, qubitization h…

Lorenzo Buffoni and Michele Campisi,

Quantum 7, 961 (2023).

We demonstrate an information erasure protocol that resets $N$ qubits at once. The method displays exceptional performances in terms of energy cost (it operates nearly at Landauer energy cost…

Yi-Ting Tu, Iksu Jang, Po-Yao Chang, and Yu-Chin Tzeng,

Quantum 7, 960 (2023).

The fidelity susceptibility is a tool for studying quantum phase transitions in the Hermitian condensed matter systems. Recently, it has been generalized with the biorthogonal basis for the…

Mathys Rennela, Sebastiaan Brand, Alfons Laarman, and Vedran Dunjko,

Quantum 7, 959 (2023).

One of the challenges of quantum computers in the near- and mid- term is the limited number of qubits we can use for computations. Finding methods that achieve useful quantum improvements un…

Lin-Qing Chen, Flaminia Giacomini, and Carlo Rovelli,

Quantum 7, 958 (2023).

Field mediated entanglement experiments probe the quantum superposition of macroscopically distinct field configurations. We show that this phenomenon can be described by using a transparent…

Satoshi Yoshida, Akihito Soeda, and Mio Murao,

Quantum 7, 957 (2023).

Isometry operations encode the quantum information of the input system to a larger output system, while the corresponding decoding operation would be an inverse operation of the encoding iso…

Christian Carisch and Oded Zilberberg,

Quantum 7, 954 (2023).

Entanglement is the key resource for quantum technologies and is at the root of exciting many-body phenomena. However, quantifying the entanglement between two parts of a real-world quantum…

Mladen Pavicic,

Quantum 7, 953 (2023).

Quantum contextual sets have been recognized as resources for universal quantum computation, quantum steering and quantum communication. Therefore, we focus on engineering the sets that supp…

Maike Drieb-Schön, Kilian Ender, Younes Javanmard, and Wolfgang Lechner,

Quantum 7, 951 (2023).

Constraints make hard optimization problems even harder to solve on quantum devices because they are implemented with large energy penalties and additional qubit overhead. The parity mapping…

Kilian Ender, Roeland ter Hoeven, Benjamin E. Niehoff, Maike Drieb-Schön, and Wolfgang Lechner,

Quantum 7, 950 (2023).

We introduce parity quantum optimization with the aim of solving optimization problems consisting of arbitrary $k$-body interactions and side conditions using planar quantum chip architectures…

Matt Menickelly, Yunsoo Ha, and Matthew Otten,

Quantum 7, 949 (2023).

Variational quantum algorithms, which have risen to prominence in the noisy intermediate-scale quantum setting, require the implementation of a stochastic optimizer on classical hardware. To…

Lorenzo Catani and Matthew Leifer,

Quantum 7, 948 (2023).

In the framework of ontological models, the inherently nonclassical features of quantum theory always seem to involve properties that are fine tuned, i.e. properties that hold at the operati…

Thinh P. Le, Chiara Meroni, Bernd Sturmfels, Reinhard F. Werner, and Timo Ziegler,

Quantum 7, 947 (2023).

In the minimal scenario of quantum correlations, two parties can choose from two observables with two possible outcomes each. Probabilities are specified by four marginals and four correlati…

Carlo Cepollaro, Flaminia Giacomini, and Matteo G.A. Paris,

Quantum 7, 946 (2023).

Atomic clock interferometers are a valuable tool to test the interface between quantum theory and gravity, in particular via the measurement of gravitational time dilation in the quantum reg…

Jorge Escandón-Monardes, Aldo Delgado, and Stephen P. Walborn,

Quantum 7, 945 (2023).

The quantum switch is a quantum computational primitive that provides computational advantage by applying operations in a superposition of orders. In particular, it can reduce the number of…

Alexandru Cojocaru, Juan Garay, Aggelos Kiayias, Fang Song, and Petros Wallden,

Quantum 7, 944 (2023).

A proof of work (PoW) is an important cryptographic construct enabling a party to convince others that they invested some effort in solving a computational task. Arguably, its main impact ha…

Salvatore Chiavazzo, Anders Søndberg Sørensen, Oleksandr Kyriienko, and Luca Dellantonio,

Quantum 7, 943 (2023).

We consider a nonlinearly coupled electromechanical system, and develop a quantitative theory for two-phonon cooling. In the presence of two-phonon cooling, the mechanical Hilbert space is e…

David F. Locher, Lorenzo Cardarelli, and Markus Müller,

Quantum 7, 942 (2023).

Active quantum error correction is a central ingredient to achieve robust quantum processors. In this paper we investigate the potential of quantum machine learning for quantum error correct…

Masahito Hayashi and Yuxiang Yang,

Quantum 7, 936 (2023).

The ability to extract relevant information is critical to learning. An ingenious approach as such is the information bottleneck, an optimisation problem whose solution corresponds to a fait…

Hassan Shapourian and Alireza Shabani,

Quantum 7, 935 (2023).

Graph states are a family of stabilizer states which can be tailored towards various applications in photonic quantum computing and quantum communication. In this paper, we present a modular…

Martin R. Albrecht, Miloš Prokop, Yixin Shen, and Petros Wallden,

Quantum 7, 933 (2023).

A fundamental computational problem is to find a shortest non-zero vector in Euclidean lattices, a problem known as the Shortest Vector Problem (SVP). This problem is believed to be hard eve…

Nicolas Heurtel, Andreas Fyrillas, Grégoire de Gliniasty, Raphaël Le Bihan, Sébastien Malherbe, Marceau Pailhas, Eric Bertasi, Boris Bourdoncle, Pierre-Emmanuel Emeriau, Rawad Mezher, Luka Music, Nadia Belabas, Benoît Valiron, Pascale Senellart, Shane Mansfield, and Jean Senellart,

Quantum 7, 931 (2023).

We introduce $Perceval$, an open-source software platform for simulating and interfacing with discrete-variable photonic quantum computers, and describe its main features and components. Its P…

Aleksander Kubica and Nicolas Delfosse,

Quantum 7, 929 (2023).

We introduce an efficient decoder of the color code in $d\geq 2$ dimensions, the Restriction Decoder, which uses any $d$-dimensional toric code decoder combined with a local lifting procedure to…

Yoshifumi Nakata, Eyuri Wakakuwa, and Masato Koashi,

Quantum 7, 928 (2023).

The Hayden-Preskill protocol is a qubit-toy model of the black hole information paradox. Based on the assumption of scrambling, it was revealed that quantum information is instantly leaked o…

José Garre-Rubio, Laurens Lootens, and András Molnár,

Quantum 7, 927 (2023).

We classify the different ways in which matrix product states (MPSs) can stay invariant under the action of matrix product operator (MPO) symmetries. This is achieved through a local charact…

Beata Zjawin, David Schmid, Matty J. Hoban, and Ana Belén Sainz,

Quantum 7, 926 (2023).

Einstein-Podolsky-Rosen (EPR) steering is often (implicitly or explicitly) taken to be evidence for spooky action-at-a-distance. An alternative perspective on steering is that Alice has no c…

Yuan Zhan, Paul Hilaire, Edwin Barnes, Sophia E. Economou, and Shuo Sun,

Quantum 7, 924 (2023).

By encoding logical qubits into specific types of photonic graph states, one can realize quantum repeaters that enable fast entanglement distribution rates approaching classical communicatio…

Zhen-Peng Xu, Jonathan Steinberg, Jaskaran Singh, Antonio J. López-Tarrida, José R. Portillo, and Adán Cabello,

Quantum 7, 922 (2023).

Bell inequality tests where the detection efficiency is below a certain threshold $\eta_{\rm{crit}}$ can be simulated with local hidden-variable models. Here, we introduce a method to identify…

Fernando A. Calderon-Vargas, Timothy Proctor, Kenneth Rudinger, and Mohan Sarovar,

Quantum 7, 921 (2023).

As the width and depth of quantum circuits implemented by state-of-the-art quantum processors rapidly increase, circuit analysis and assessment via classical simulation are becoming unfeasib…

Luís Bugalho, Bruno C. Coutinho, Francisco A. Monteiro, and Yasser Omar,

Quantum 7, 920 (2023).

A quantum internet aims at harnessing networked quantum technologies, namely by distributing bipartite entanglement between distant nodes. However, multipartite entanglement between the node…

Markus Penz and Robert van Leeuwen,

Quantum 7, 918 (2023).

In a previous work [J. Chem. Phys. 155, 244111 (2021)], we found counterexamples to the fundamental Hohenberg-Kohn theorem from density-functional theory in finite-lattice systems represente…

Mingxia Huo and Ying Li,

Quantum 7, 916 (2023).

Computing the ground-state properties of quantum many-body systems is a promising application of near-term quantum hardware with a potential impact in many fields. The conventional algorithm…

Giuseppe Vitagliano, Matteo Fadel, Iagoba Apellaniz, Matthias Kleinmann, Bernd Lücke, Carsten Klempt, and Géza Tóth,

Quantum 7, 914 (2023).

We present a method to detect bipartite entanglement based on number-phase-like uncertainty relations in split spin ensembles. First, we derive an uncertainty relation that plays the role of…

Shi-Xin Zhang, Jonathan Allcock, Zhou-Quan Wan, Shuo Liu, Jiace Sun, Hao Yu, Xing-Han Yang, Jiezhong Qiu, Zhaofeng Ye, Yu-Qin Chen, Chee-Kong Lee, Yi-Cong Zheng, Shao-Kai Jian, Hong Yao, Chang-Yu Hsieh, and Shengyu Zhang,

Quantum 7, 912 (2023).

TensorCircuit is an open source quantum circuit simulator based on tensor network contraction, designed for speed, flexibility and code efficiency. Written purely in Python, and built on top…

Dardo Goyeneche, Wojciech Bruzda, Ondřej Turek, Daniel Alsina, and Karol Życzkowski,

Quantum 7, 911 (2023).

The problem of computing the local hidden variable (LHV) value of a Bell inequality plays a central role in the study of quantum nonlocality. In particular, this problem is the first step to…

Cheng-Ju Lin, Weicheng Ye, Yijian Zou, Shengqi Sang, and Timothy H. Hsieh,

Quantum 7, 910 (2023).

The sign structure of quantum states is closely connected to quantum phases of matter, yet detecting such fine-grained properties of amplitudes is subtle. Here we employ as a diagnostic meas…

Christa Zoufal, Ryan V. Mishmash, Nitin Sharma, Niraj Kumar, Aashish Sheshadri, Amol Deshmukh, Noelle Ibrahim, Julien Gacon, and Stefan Woerner,

Quantum 7, 909 (2023).

We introduce a variational quantum algorithm to solve unconstrained black box binary optimization problems, i.e., problems in which the objective function is given as black box. This is in c…

Robert de Keijzer, Oliver Tse, and Servaas Kokkelmans,

Quantum 7, 908 (2023).

This work studies pulse based variational quantum algorithms (VQAs), which are designed to determine the ground state of a quantum mechanical system by combining classical and quantum hardwa…

Bradley Longstaff and Jonatan Bohr Brask,

Quantum 7, 907 (2023).

We investigate nonlocal quantum correlations arising between multiple two-level impurity atoms coupled to an ultracold bosonic gas. We find that the environment-induced dynamics of the impur…

Ariel Shlosberg, Andrew J. Jena, Priyanka Mukhopadhyay, Jan F. Haase, Felix Leditzky, and Luca Dellantonio,

Quantum 7, 906 (2023).

The accurate estimation of quantum observables is a critical task in science. With progress on the hardware, measuring a quantum system will become increasingly demanding, particularly for v…

Davide Rattacaso, Gianluca Passarelli, and Procolo Lucignano,

Quantum 7, 905 (2023).

Learning the unknown Hamiltonian governing the dynamics of a quantum many-body system is a challenging task. In this manuscript, we propose a possible strategy based on repeated measurements…

Ferran Riera-Sàbat, Pavel Sekatski, and Wolfgang Dür,

Quantum 7, 904 (2023).

We consider a system of multiple qubits without any quantum control. We show that one can mediate entanglement between different subsystems in a controlled way by adding a (locally) controll…

Minjie Wang, Shengzhi Wang, Tengfei Ma, Ya Li, Yan Xie, Haole Jiao, Hailong Liu, Shujing Li, and Hai Wang,

Quantum 7, 903 (2023).

Qubit memory that is entangled with photonic qubit is the building block for long distance quantum repeaters. Cavity enhanced and long lived spin wave photon entanglement has been demonstrat…

Shalev Ben-David and Or Sattath,

Quantum 7, 901 (2023).

The fisherman caught a quantum fish. "Fisherman, please let me go", begged the fish, "and I will grant you three wishes". The fisherman agreed. The fish gave the fisherman a quantum computer…

Victoria J Wright and Ravi Kunjwal,

Quantum 7, 900 (2023).

The Kochen–Specker (KS) theorem reveals the nonclassicality of single quantum systems. In contrast, Bell's theorem and entanglement concern the nonclassicality of composite quantum systems.…

Valentin Gebhart and Augusto Smerzi,

Quantum 7, 897 (2023).

Discarding undesirable measurement results in Bell experiments opens the detection loophole that prevents a conclusive demonstration of nonlocality. As closing the detection loophole represe…

Giancarlo Gatti, Daniel Huerga, Enrique Solano, and Mikel Sanz,

Quantum 7, 895 (2023).

We propose a protocol to encode classical bits in the measurement statistics of many-body Pauli observables, leveraging quantum correlations for a random access code. Measurement contexts bu…

Casper Gyurik, Dyon Vreumingen, van, and Vedran Dunjko,

Quantum 7, 893 (2023).

Quantum machine learning (QML) models based on parameterized quantum circuits are often highlighted as candidates for quantum computing's near-term “killer application''. However, the unders…

Xinyu Fei, Lucas T. Brady, Jeffrey Larson, Sven Leyffer, and Siqian Shen,

Quantum 7, 892 (2023).

Quantum control aims to manipulate quantum systems toward specific quantum states or desired operations. Designing highly accurate and effective control steps is vitally important to various…

Henry Yuen,

Quantum 7, 890 (2023).

We show that $\Omega(rd/\epsilon)$ copies of an unknown rank-$r$, dimension-$d$ quantum mixed state are necessary in order to learn a classical description with $1 – \epsilon$ fidelity. This improve…

Guy Braiman, Ori Reinhardt, Chen Mechel, Omer Levi, and Ido Kaminer,

Quantum 7, 888 (2023).

Recent advances in laser interactions with coherent free electrons have enabled to shape the electron's quantum state. Each electron becomes a superposition of energy levels on an infinite q…