Quantum 6, 667 (2022). https://doi.org/10.22331/q-2022-03-11-667 Quantum error correcting codes (QECCs) are the means of choice whenever quantum systems suffer errors, e.g., due to imperfect devices, environments, or faulty channels. By now, a plethora of families […]
Quantum 6, 666 (2022). https://doi.org/10.22331/q-2022-03-11-666 In this paper we describe an algebraic/geometrical approach to quantum scrambling. Generalized quantum subsystems are described by an hermitian-closed unital subalgebra $cal A$ of operators evolving through a unitary channel. […]
Quantum 6, 665 (2022). https://doi.org/10.22331/q-2022-03-10-665 Multiparameter quantum estimation is made difficult by the following three obstacles. First, incompatibility among different physical quantities poses a limit on the attainable precision. Second, the ultimate precision is not […]
Quantum 6, 664 (2022). https://doi.org/10.22331/q-2022-03-03-664 This article proposes the first discrete-time implementation of Rydberg quantum walk in multi-dimensional spatial space that could ideally simulate different classes of topological insulators. Using distance-selective exchange-interaction between Rydberg excited […]
Quantum 6, 663 (2022). https://doi.org/10.22331/q-2022-03-01-663 The causal order of events need not be fixed: whether a bus arrives before or after another at a certain stop can depend on other variables – like traffic. Coherent […]
Quantum 6, 662 (2022). https://doi.org/10.22331/q-2022-03-01-662 For a classical channel, neither the Shannon ca-pa-city, nor the sum of conditional probabilities corresponding to the cases of successful transmission can be increased by the use of shared entanglement, […]
Scientists have long made digital simulations of the universe on the grandest scales. Now they’re turning their attention to smaller systems—though those systems are no less grand. The cells in our bodies are like their […]
Quantum 6, 661 (2022). https://doi.org/10.22331/q-2022-02-24-661 We introduce the hemicubic codes, a family of quantum codes obtained by associating qubits with the $p$-faces of the $n$-cube (for $n>p$) and stabilizer constraints with faces of dimension $(ppm1)$. […]
Quantum 6, 660 (2022). https://doi.org/10.22331/q-2022-02-24-660 Many applications in quantum communication, sensing and computation need provably quantum non-Gaussian light. Recently such light, witnessed by a negative Wigner function, has been estimated using homodyne tomography from a […]
Quantum 6, 659 (2022). https://doi.org/10.22331/q-2022-02-21-659 Spekkens has introduced an $textit{epistemically restricted classical theory}$ of discrete systems, based on discrete phase space. The theory manifests a number of quantum-like properties but cannot fully imitate quantum theory […]
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