Category: singularityhub

Quantum 7, 1038 (2023). https://doi.org/10.22331/q-2023-06-07-1038 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 the context of the conditional […]

Quantum 7, 1037 (2023). https://doi.org/10.22331/q-2023-06-07-1037 Belief propagation (BP) is well-known as a low complexity decoding algorithm with a strong performance for important classes of quantum error correcting codes, e.g. notably for the quantum low-density parity […]

Quantum 7, 1036 (2023). https://doi.org/10.22331/q-2023-06-07-1036 Given a dataset of input states, measurements, and probabilities, is it possible to efficiently predict the measurement probabilities associated with a quantum circuit? Recent work of Caro and Datta (2020) […]

Quantum 7, 1035 (2023). https://doi.org/10.22331/q-2023-06-07-1035 While there is general consensus on the definition of incompatible POVMs, moving up to the level of instruments one finds a much less clear situation, with mathematically different and logically […]

Quantum 7, 1034 (2023). https://doi.org/10.22331/q-2023-06-06-1034 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 […]

Quantum 7, 1033 (2023). https://doi.org/10.22331/q-2023-06-05-1033 Measurement error and disturbance, in the presence of conservation laws, are analysed in general operational terms. We provide novel quantitative bounds demonstrating necessary conditions under which accurate or non-disturbing measurements […]

Quantum 7, 1032 (2023). https://doi.org/10.22331/q-2023-06-05-1032 Quantum computers often manipulate physical qubits encoded on two-level quantum systems. Bosonic qubit codes depart from this idea by encoding information in a well-chosen subspace of an infinite-dimensional Fock space. […]

Quantum 7, 1031 (2023). https://doi.org/10.22331/q-2023-06-02-1031 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. This paper presents […]

Quantum 7, 1030 (2023). https://doi.org/10.22331/q-2023-06-02-1030 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 speedups for nonconvex optimization […]