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Related papers: Verification of joint measurability using phase-sp…

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We discuss the connection between the incompatibility of quantum measurements, as captured by the notion of joint measurability, and the violation of Bell inequalities. Specifically, we present explicitly a given a set of non jointly…

Quantum Physics · Physics 2018-02-02 Flavien Hirsch , Marco Túlio Quintino , Nicolas Brunner

We demonstrate that the negative volume of any $s$-paramatrized quasiprobability, including the Glauber-Sudashan $P$-function, can be consistently defined and forms a continuous hierarchy of nonclassicality measures that are linear optical…

Quantum Physics · Physics 2020-03-25 Kok Chuan Tan , Seongjeon Choi , Hyunseok Jeong

We address continuous weak linear quantum measurement and argue that it is best understood in terms of statistics of the outcomes of the linear detectors measuring a quantum system, for example, a qubit. We mostly concentrate on a setup…

Mesoscale and Nanoscale Physics · Physics 2008-07-14 Hongduo Wei , Yuli V. Nazarov

We consider a quantity that is the differential relative entropy between a generic Wigner function and a Gaussian one. We prove that said quantity is minimized with respect to its Gaussian argument, if both Wigner functions in the argument…

Heisenberg's uncertainty principle has recently led to general measurement uncertainty relations for quantum systems: incompatible observables can be measured jointly or in sequence only with some unavoidable approximation, which can be…

Quantum Physics · Physics 2017-06-27 Alberto Barchielli , Matteo Gregoratti , Alessandro Toigo

Complementarity, the incomplete nature of a quantum measurement - a core concept in quantum mechanics - stems from the choice of the measurement apparatus. The notion of complementarity is closely related to Heisenberg's uncertainty…

Mesoscale and Nanoscale Physics · Physics 2015-06-17 E. Weisz , H. K. Choi , I. Sivan , M. Heiblum , Y. Gefen , D. Mahalu , V. Umansky

To understand quantum optics experiments, we must perform calculations that consider the principal sources of noise, such as losses, spectral impurity and partial distinguishability. In both discrete and continuous variable systems, these…

Quantum Physics · Physics 2025-08-15 Jacob F. F. Bulmer , Javier Martínez-Cifuentes , Bryn A. Bell , Nicolás Quesada

We provide a rigorous derivation of a quantum filter for the case of multiple measurements being made on a quantum system. We consider a class of measurement processes which are functions of bosonic field operators, including combinations…

Mathematical Physics · Physics 2017-07-25 Muhammad F. Emzir , Matthew J. Woolley , Ian R. Petersen

We investigate a measure of quantum coherence and its extension to quantify quantum macroscopicity. The coherence measure can also quantify the asymmetry of a quantum state with respect to a given group transformation. We then show that a…

Quantum Physics · Physics 2018-02-14 Hyukjoon Kwon , Chae-Yeun Park , Kok Chuan Tan , Daekun Ahn , Hyunseok Jeong

Necessary and sufficient conditions for the nonclassicality of bosonic quantum states are formulated by introducing nonclassicality filters and nonclassicality quasiprobability distributions. Regular quasiprobabilities are constructed from…

Quantum Physics · Physics 2015-03-14 T. Kiesel , W. Vogel

Recent work has revealed the central role played by the Kirkwood-Dirac quasiprobability (KDQ) as a tool to properly account for non-classical features in the context of condensed matter physics (scrambling, dynamical phase transitions)…

We use the exact calculation of the quantum mechanical, temporal characteristic function $\chi(\eta)$ and the degree of second-order coherence $g^{(2)}(\tau)$ for a single-mode, degenerate parametric amplifier for a system in the Gaussian…

Quantum Physics · Physics 2016-11-23 Moorad Alexanian

Measurement in quantum mechanics is notoriously unpredictable. The uncertainty in quantum measurement can arise from the noncommutativity between the state and the measurement basis which is intrinsically quantum, but it may also be of…

Quantum Physics · Physics 2024-12-17 Agung Budiyono

After a derivation of the quantum Bayes theorem, and a discussion of the reconstruction of the unknown state of identical spin systems by repeated measurements, the main part of this paper treats the problem of determining the unknown phase…

Quantum Physics · Physics 2009-11-11 Filippo Neri

We propose an experiment demonstrating the nonlocality of a quantum singlet-like state generated from a single photon incident on a beam splitter. Each of the two spatially separated apparatuses in the setup performs a strongly unbalanced…

Quantum Physics · Physics 2009-10-31 Konrad Banaszek , Krzysztof Wodkiewicz

Chained correlation inequalities involving pairwise correlations of qubit observables in the equatorial plane are constructed based on the positivity of a sequence of moment matrices. When a jointly measurable set of fuzzy POVMs is employed…

Quantum Physics · Physics 2017-05-17 H. S. Karthik , A. R. Usha Devi , J. Prabhu Tej , A. K. Rajagopal , Sudha , A. Narayanan

We use fidelity susceptibility to calculate quantum critical scaling exponents for a system consisting of $N$ identical bosons interacting with a single impurity atom in a double well potential (bosonic Josephson junction). Above a critical…

Quantum Gases · Physics 2014-12-22 J. Mumford , D. H. J. O'Dell

Derivation and experimental violation of Bell-like inequalities involve the measurement of in-compatible observables. Simple complementarity forbids the existence of such joint probabilitydistribution. Moreover, the measurement of…

Quantum Physics · Physics 2020-06-18 Elisa Masa , Laura Ares , Alfredo Luis

We develop a general framework to investigate fluctuations of non-commuting observables. To this end, we consider the Keldysh quasi-probability distribution (KQPD). This distribution provides a measurement-independent description of the…

Quantum Physics · Physics 2017-10-13 Patrick P. Hofer

We introduce the concept of degree of quantumness in quantum synchronization, a measure of the quantum nature of synchronization in quantum systems. Following techniques from quantum information, we propose the number of non-commuting…

Quantum Physics · Physics 2020-01-06 H. Eneriz , D. Z. Rossatto , F. A. Cárdenas-L'opez , E. Solano , M. Sanz
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