Quantum

Paper

Optimization of the surface code design for Majorana-based qubits

Rui Chao, Michael E. Beverland, Nicolas Delfosse, and Jeongwan Haah,

Quantum 4, 352 (2020).

The surface code is a prominent topological error-correcting code exhibiting high fault-tolerance accuracy thresholds. Conventional schemes for error correction with the surface code place q…

Paper

Classical Simulations of Quantum Field Theory in Curved Spacetime I: Fermionic Hawking-Hartle Vacua from a Staggered Lattice Scheme

Adam G. M. Lewis and Guifré Vidal,

Quantum 4, 351 (2020).

We numerically compute renormalized expectation values of quadratic operators in a quantum field theory (QFT) of free Dirac fermions in curved two-dimensional (Lorentzian) spacetime. First,…

Paper

Emergence of the Born rule in quantum optics

Brian R. La Cour and Morgan C. Williamson,

Quantum 4, 350 (2020).

The Born rule provides a fundamental connection between theory and observation in quantum mechanics, yet its origin remains a mystery. We consider this problem within the context of quantum…

Paper

A three-player coherent state embezzlement game

Zhengfeng Ji, Debbie Leung, and Thomas Vidick,

Quantum 4, 349 (2020).

We introduce a three-player nonlocal game, with a finite number of classical questions and answers, such that the optimal success probability of $1$ in the game can only be achieved in the lim…

Paper

Transforming graph states to Bell-pairs is NP-Complete

Axel Dahlberg, Jonas Helsen, and Stephanie Wehner,

Quantum 4, 348 (2020).

Critical to the construction of large scale quantum networks, i.e. a quantum internet, is the development of fast algorithms for managing entanglement present in the network. One fundamental…

Paper

Environmentally Induced Entanglement – Anomalous Behavior in the Adiabatic Regime

Richard Hartmann and Walter T. Strunz,

Quantum 4, 347 (2020).

Considering two non-interacting qubits in the context of open quantum systems, it is well known that their common environment may act as an entangling agent. In a perturbative regime the inf…

Paper

A generalization of CHSH and the algebraic structure of optimal strategies

David Cui, Arthur Mehta, Hamoon Mousavi, and Seyed Sajjad Nezhadi,

Quantum 4, 346 (2020).

$\textit{Self-testing}$ has been a rich area of study in quantum information theory. It allows an experimenter to interact classically with a black box quantum system and to test that a specif…

Paper

Quantum prescriptions are more ontologically distinct than they are operationally distinguishable

Anubhav Chaturvedi and Debashis Saha,

Quantum 4, 345 (2020).

Based on an intuitive generalization of the Leibniz principle of `the identity of indiscernibles', we introduce a novel ontological notion of classicality, called bounded ontological distinc…

Paper

Bounding sets of sequential quantum correlations and device-independent randomness certification

Joseph Bowles, Flavio Baccari, and Alexia Salavrakos,

Quantum 4, 344 (2020).

An important problem in quantum information theory is that of bounding sets of correlations that arise from making local measurements on entangled states of arbitrary dimension. Currently, t…

Paper

Probing nonclassicality with matrices of phase-space distributions

Martin Bohmann, Elizabeth Agudelo, and Jan Sperling,

Quantum 4, 343 (2020).

We devise a method to certify nonclassical features via correlations of phase-space distributions by unifying the notions of quasiprobabilities and matrices of correlation functions. Our app…

Paper

A quantum extension of SVM-perf for training nonlinear SVMs in almost linear time

Jonathan Allcock and Chang-Yu Hsieh,

Quantum 4, 342 (2020).

We propose a quantum algorithm for training nonlinear support vector machines (SVM) for feature space learning where classical input data is encoded in the amplitudes of quantum states. Base…

Paper

Yao.jl: Extensible, Efficient Framework for Quantum Algorithm Design

Xiu-Zhe Luo, Jin-Guo Liu, Pan Zhang, and Lei Wang,

Quantum 4, 341 (2020).

We introduce $\texttt{Yao}$, an extensible, efficient open-source framework for quantum algorithm design. $\texttt{Yao}$ features generic and differentiable programming of quantum circuits. It a…

Paper

Transfer learning in hybrid classical-quantum neural networks

Andrea Mari, Thomas R. Bromley, Josh Izaac, Maria Schuld, and Nathan Killoran,

Quantum 4, 340 (2020).

We extend the concept of transfer learning, widely applied in modern machine learning algorithms, to the emerging context of hybrid neural networks composed of classical and quantum elements…

Paper

Weak-ergodicity-breaking via lattice supersymmetry

Federica Maria Surace, Giuliano Giudici, and Marcello Dalmonte,

Quantum 4, 339 (2020).

We study the spectral properties of $D$-dimensional $N=2$ supersymmetric lattice models. We find systematic departures from the eigenstate thermalization hypothesis (ETH) in the form of a degene…

Paper

Morphophoric POVMs, generalised qplexes, and 2-designs

Wojciech Słomczyński and Anna Szymusiak,

Quantum 4, 338 (2020).

We study the class of quantum measurements with the property that the image of the set of quantum states under the measurement map transforming states into probability distributions is simil…

Paper

Self-testing of quantum systems: a review

Ivan Šupić and Joseph Bowles,

Quantum 4, 337 (2020).

Self-testing is a method to infer the underlying physics of a quantum experiment in a black box scenario. As such it represents the strongest form of certification for quantum systems. In re…

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