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Related papers: Comparing quantumness criteria

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We provide a theory independent framework to quantify coherence. In comparison with Bell's theory independent approach to quantum nonlocality, we characterize a general coherence phenomenon with statistics arising from sequential…

Quantum Physics · Physics 2018-02-02 Liang-Liang Sun , Fei-Lei Xiong , Sixia Yu , Zeng-Bing Chen

Entanglement and coherence are fundamental properties of quantum systems, promising to power near future quantum technologies, such as quantum computation, quantum communication and quantum metrology. Yet, their quantification, rather than…

Quantum discord goes beyond entanglement and exists in a wide range of quantum states that may be separable, playing a crucial role in quantum information tasks. In this paper, we firstly proposed a zero-discord criterion for two-qubit…

Quantum Physics · Physics 2024-08-13 Wang Yiding , Huang Xiaofen , Zhang Tinggui

To exploit a given physical system for quantum information processing, it is critical to understand the different types of noise affecting quantum control. Distinguishing coherent and incoherent errors is extremely useful as they can be…

The superposition of quantum states lies at the heart of physics and has been recently found to serve as a versatile resource for quantum information protocols, defining the notion of quantum coherence. In this contribution, we report on…

Quantum Physics · Physics 2019-10-16 Valeria Cimini , Ilaria Gianani , Marco Sbroscia , Jan Sperling , Marco Barbieri

One of the best signatures of nonclassicality in a quantum system is the existence of correlations that have no classical counterpart. Different methods for quantifying the quantum and classical parts of correlations are amongst the more…

Quantum Physics · Physics 2012-11-29 Kavan Modi , Aharon Brodutch , Hugo Cable , Tomasz Paterek , Vlatko Vedral

Quantum state smoothing is a technique for estimating the quantum state of a partially observed quantum system at time $\tau$, conditioned on an entire observed measurement record (both before and after $\tau$). However, this smoothing…

Quantum Physics · Physics 2020-04-14 Kiarn T. Laverick , Areeya Chantasri , Howard M. Wiseman

We propose a directly measurable criterion for the entanglement of two qubits. We compare the criterion with other criteria, and we find that for pure states, and some mixed states, it coincides with the state's concurrency. The measure can…

Quantum Physics · Physics 2016-08-16 Hoshang Heydari , Gunnar Björk , Luis Sánchez-Soto

Different approaches in quantifying environmentally-induced decoherence are considered. We identify a measure of decoherence, derived from the density matrix of the system of interest, that quantifies the environmentally induced error,…

Mesoscale and Nanoscale Physics · Physics 2010-10-12 Arkady Fedorov , Leonid Fedichkin , Vladimir Privman

Correlations obtained from sequences of measurements have been employed to distinguish among different physical theories or to witness the dimension of a system. In this work we show that they can also be used to establish semi-device…

Quantum Physics · Physics 2020-10-23 Cornelia Spee

Quantification of coherence lies at the heart of quantum information processing and fundamental physics. Exact evaluation of coherence measures generally needs a full reconstruction of the density matrix, which becomes intractable for…

Quantum Physics · Physics 2021-06-28 Qi-Ming Ding , Xiao-Xu Fang , Xiao Yuan , Ting Zhang , He Lu

We propose an experiment to test Bell's inequality violation in condensed-matter physics. We show how to generate, manipulate and detect entangled states using ballistic electrons in Coulomb-coupled semiconductor quantum wires. Due to its…

Quantum Physics · Physics 2009-11-06 Radu Ionicioiu , Paolo Zanardi , Fausto Rossi

In relation of observable and quantum state, the entity $I_C$ from previous work quantifies simultaneously coherence, incompatibility and quantumness. In this article its application to quantum correlations in bipartite states is studied.…

Quantum Physics · Physics 2007-05-23 Fedor Herbut

We present new bell inequalities for arbitrary dimensional bipartite quantum systems. The maximal violation of the inequalities is computed. The Bell inequality is capable of detecting quantum entanglement of both pure and mixed quantum…

Quantum Physics · Physics 2015-05-27 Ming Li , Shao-Ming Fei , Xianqing Li-Jost

We address the quantification of nonlinearity for quantum oscillators and introduce two measures based on the properties of the ground state rather than on the form of the potential itself. The first measure is a fidelity-based one, and…

Quantum Physics · Physics 2015-01-22 Matteo G. A. Paris , Marco G. Genoni , Nathan Shammah , Berihu Teklu

A quantitative measure of quantum coherence was recently introduced, in the context of quantum information theory. This measure has also been propounded as a good quantifier of the wave nature of quantum objects. However, actually measuring…

Quantum Physics · Physics 2017-04-12 Tania Paul , Tabish Qureshi

We describe and realize an experimental procedure for assessing the incompatibility of two qubit measurements. The experiment consists in a state discrimination task where either measurement is used according to some partial intermediate…

In the quantitative theory of quantum coherence, the amount of coherence for given states can be meaningfully discussed only when referring to a preferred basis. One of the objections to this quantification is that the amount of coherence…

Quantum Physics · Physics 2024-12-11 Zhi-Xiang Jin , Yuan-Hong Tao , Bing Yu , Shao-Ming Fei

We compare entanglement with quantum nonlocality employing a geometric structure of the state space of bipartite qudits. Central object is a regular simplex spanned by generalized Bell states. The Collins-Gisin-Linden-Massar-Popescu-Bell…

Quantum Physics · Physics 2015-03-13 Christoph Spengler , Marcus Huber , Beatrix C. Hiesmayr

Coherence underlies quantum phenomena, yet it is manifest in classical theories; delineating coherence's role is a fickle business. The quadrature coherence scale (QCS) was invented to remove such ambiguity, quantifying quantum features of…

Quantum Physics · Physics 2023-04-19 Aaron Z. Goldberg , Guillaume S. Thekkadath , Khabat Heshami