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Related papers: Determining quantum coherence with minimal resourc…

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Being the key resource in quantum physics, the proper quantification of coherence is of utmost importance. Amid complex-looking functionals in quantifying coherence, we set forth a simple and easy-to-evaluate approach: Principal diagonal…

Quantum Physics · Physics 2023-02-08 Manis Hazra , Debabrata Goswami

Quantum discrimination and estimation are pivotal for many quantum technologies, and their performance depends on the optimal choice of probe state and measurement. Here we show that their performance can be further improved by suitably…

Quantum Physics · Physics 2020-09-14 Daniel Basilewitsch , Haidong Yuan , Christiane P. Koch

Quantum communication, while promising unparalleled security, faces significant practical challenges due to imperfections in quantum devices, particularly in single-photon detectors (SPDs). One of the key issues is the impact of dark…

Quantum Physics · Physics 2024-12-12 Hao Shu

We investigate the extent to which ``interaction-free'' measurements perturb the state of quantum systems. We show that the absence of energy exchange during the measurement is not a sufficient criterion to preserve that state, as the…

Quantum Physics · Physics 2009-11-06 S. Potting , E. S. Lee , W. Schmitt , I. Rumyantsev , B. Mohring , P. Meystre

The resource theory of coherence addresses the extent to which quantum properties are present in a given quantum system. While coherence has been extensively studied for individual quantum states, measures of coherence for ensembles of…

Quantum Physics · Physics 2025-10-02 Aleksei Kodukhov

An orthogonal set of states in multipartite systems is called to be strong quantum nonlocality if it is locally irreducible under every bipartition of the subsystems…

Quantum Physics · Physics 2023-09-13 Mao-Sheng Li , Yan-Ling Wang

We study the verification of maximally entangled states by virtue of the simplest measurement settings: local projective measurements without adaption. We show that optimal protocols are in one-to-one correspondence with complex projective…

Quantum Physics · Physics 2020-01-01 Huangjun Zhu , Masahito Hayashi

We study a decoherence reduction scheme that involves an intermediate measurement on the qubit in an equal superposition basis, in the general framework of all qubit-environment interactions that lead to qubit pure decoherence. We show…

Quantum Physics · Physics 2024-02-22 Bartosz Rzepkowski , Katarzyna Roszak

Quantum coherence plays a fundamental and operational role in different areas of physics. A resource theory has been developed to characterize the coherence of distinguishable particles systems. Here we show that indistinguishability of…

We consider two different optimized measurement strategies for the discrimination of nonorthogonal quantum states. The first is conclusive discrimination with a minimum probability of inferring an erroneous result, and the second is…

Quantum Physics · Physics 2009-11-10 Ulrike Herzog , Janos A. Bergou

Quantum state discrimination is a central problem in quantum measurement theory, with applications spanning from quantum communication to computation. Typical measurement paradigms for state discrimination involve a minimum probability of…

Quantum Physics · Physics 2022-07-26 M. T. DiMario , F. E. Becerra

Identification of nonorthogonal quantum states without error is crucial for various applications in quantum information technology, as well as the foundations of quantum physics. Theoretical studies have proposed measurements that maximize…

Quantum Physics · Physics 2026-03-11 Kang-Min Hu , Min Namkung , Myung-Hyun Sohn , Hyang-Tag Lim

Quantifying entanglement is a work in progress which is important for the active field of quantum information and computation. A measure of bipartite pure state entanglement is proposed here, named entanglement coherence, which is…

Quantum Physics · Physics 2022-02-15 Neha Pathania , Tabish Qureshi

We investigate the ultimate precision limits for quantum phase estimation in terms of the coherence, $C$, of the probe. For pure states, we give the minimum estimation variance attainable, $V(C)$, and the optimal state, in the asymptotic…

Quantum Physics · Physics 2022-07-13 D. Munoz-Lahoz , J. Calsamiglia , J. A. Bergou , E. Bagan

For any finite dimensional Hilbert space, we construct explicitly five orthonormal bases such that the corresponding measurements allow for efficient tomography of an arbitrary pure quantum state. This means that such measurements can be…

Quantum Physics · Physics 2016-09-14 Claudio Carmeli , Teiko Heinosaari , Michael Kech , Jussi Schultz , Alessandro Toigo

Using quantum measurements to extract information from states is a matter of routine in quantum science and technologies. A recent work [Phys. Rev. Lett. 133, 040202 (2024)] reported the finding that the symmetric structures of a state can…

Quantum Physics · Physics 2025-02-18 Zhao-Yi Zhou , Da-Jian Zhang

Estimating the unitarity of an unknown quantum channel $\mathcal{E}$ provides information on how much it is unitary, which is a basic and important problem in quantum device certification and benchmarking. Unitarity estimation can be…

Quantum Physics · Physics 2026-02-23 Kean Chen , Qisheng Wang , Peixun Long , Mingsheng Ying

We provide a coherence-based approach to nonclassical behavior by means of distance measures. We develop a quantitative relation between coherence and nonclassicality quantifiers, which establish the nonclassicality as the maximum…

Quantum Physics · Physics 2022-07-20 Laura Ares , Alfredo Luis

Quantum sensing with undetected photons is a technique where photons of one wavelength probe a sample, but information is extracted by measuring photons of another wavelength that never interacts with the sample. This has seen significant…

Measuring the quantumness of a system can be done with a variety of methods. In this article we compare different criteria, namely quantum discord, Bell inequality violation and non-separability, for systems placed in a Gaussian state. When…

Quantum Physics · Physics 2023-04-19 Jerome Martin , Amaury Micheli , Vincent Vennin