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Related papers: Super quantum discord for X-type states

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Quantum discord is a manifestation of quantum correlations due to non-commutativity rather than entanglement. Two measures of quantum discord by the amount of non-commutativity via the trace norm and the Hilbert-Schmidt norm respectively…

Quantum Physics · Physics 2016-05-03 Yu Guo

We theoretically describe the weak measurement of a two-level system (qubit) and quantify the degree to which such a qubit measurement has a quantum non-demolition (QND) character. The qubit is coupled to a harmonic oscillator which…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 Luca Chirolli , Guido Burkard

Composite quantum systems can be in generic states characterized not only by entanglement, but also by more general quantum correlations. The interplay between these two signatures of nonclassicality is still not completely understood. In…

Quantum Physics · Physics 2011-11-17 Davide Girolami , Gerardo Adesso

We give the explicit expressions of the pairwise quantum correlations present in superpositions of multipartite coherent states. A special attention is devoted to the evaluation of the geometric quantum discord. The dynamics of quantum…

Quantum Physics · Physics 2015-06-11 M. Daoud , R. Ahl Laamara

Quantum correlation includes quantum entanglement and quantum discord. Both entanglement and discord have a common necessary condition--------quantum coherence or quantum superposition. In this paper, we attempt to give an alternative…

Quantum Physics · Physics 2014-09-23 Chang-shui Yu , Yang Zhang , Haiqing Zhao

We study the relative strength of classical and quantum correlations, as measured by discord, for two-qubit states. Quantum correlations appear only in the presence of classical correlations, while the reverse is not always true. We…

Quantum Physics · Physics 2011-01-17 Fernando Galve , Gian Luca Giorgi , Roberta Zambrini

We investigate the geometric picture of the level surfaces of quantum entanglement and geometric measure of quantum discord (GMQD) of a class of X-states, respectively. This pictorial approach provides us a direct understanding of the…

Quantum Physics · Physics 2013-12-03 Wei Song , Long-Bao Yu , Ping Dong , Da-Chuang Li , Ming Yang , Zhuo-Liang Cao

In an initially uncorrelated mixed separable bi-partite system, quantum correlations can emerge under the action of a local measurement or local noise [A. Streltsov, H. Kampermann, and D. Bru\ss{}, Phys. Rev. Lett. 107, 170502 (2011)]. We…

Quantum Physics · Physics 2015-06-17 Richard Tatham , Natalia Korolkova

Quantum technology has been rapidly growing due to its potential revolutionary applications. In particular, superconducting qubits provide a strong light-matter interaction as required for quantum computation and in principle can be scaled…

Quantum Physics · Physics 2019-04-23 Mahdi Naghiloo

Quantum discord as a measure of the quantum correlations cannot be easily computed for most of density operators. In this paper, we present a measure of the total quantum correlations that is operationally simple and can be computed…

Quantum Physics · Physics 2016-04-19 Javad Behdani , Seyed Javad Akhtarshenas , Mohsen Sarbishaei

Intrinsic quantum correlations of weak coherent states are observed between two parties through a novel detection scheme, which can be used as a supplement to the existence decoy-state BB84 and differential phase-shift quantum key…

Quantum Physics · Physics 2011-02-10 Yong Meng Sua , Erin Scanlon , Travis Beaulieu , Viktor Bollen , Kim Fook Lee

The quantum state discrimination problem is to distinguish between non-orthogonal quantum states. This problem has many applications in quantum information theory, quantum communication and quantum cryptography. In this paper a quantum…

Quantum Physics · Physics 2021-02-25 Doha A. Rizk , Ahmed Younes

We investigate and compare three distinguished geometric measures of bipartite quantum correlations that have been recently introduced in the literature: the geometric discord, the measurement-induced geometric discord, and the discord of…

Quantum Physics · Physics 2016-05-26 Wojciech Roga , Dominique Spehner , Fabrizio Illuminati

We explore the possibility of using "weak measurements" without "weak value" for quantum state estimation. Since for weak measurements the disturbance caused during each measurement is small, we can rescue the state, unlike for the case of…

Quantum Physics · Physics 2019-07-23 Debmalya Das , Arvind

Recently, the authors [arXiv quant-ph 1209.3706] studied quantum discord for Werner mixed states based on the four entangled coherent states, which are used for quantum teleportation of single qubit information encoded in superposed…

Quantum Physics · Physics 2012-10-09 Ajay K Maurya , Manoj K Mishra , Hari Prakash

It is known that a reliable geometric quantifier of discord-like correlations can be built by employing the so-called trace distance. This is used to measure how far the state under investigation is from the closest "classical-quantum" one.…

Quantum Physics · Physics 2014-01-24 F. Ciccarello , T. Tufarelli , V. Giovannetti

A goal of the emerging field of quantum control is to develop methods for quantum technologies to function robustly in the presence of noise. Central issues are the fundamental limitations on the available information about quantum systems…

Quantum correlation cost (QCC) characterizing how much quantum correlation is used in a weak-measurement process is presented based on the trace norm. It is shown that the QCC is related to the trace-norm-based quantum discord (TQD) by only…

Quantum Physics · Physics 2014-12-01 Jun Zhang , Shao-xiong Wu , Chang-shui Yu

We investigate the power of weak measurements in the framework of quantum state discrimination. First, we define and analyze the notion of weak consecutive measurements. Our main result is a convergence theorem whereby we demonstrate when…

Quantum Physics · Physics 2015-06-23 Boaz Tamir , Eliahu Cohen , Avner Priel

There has been an increasing interest in exploring quantities associated with quantum information at colliders. We perform a detailed analysis describing how to measure the quantum discord in the top anti-top quantum state at the Large…

High Energy Physics - Phenomenology · Physics 2025-03-05 Tao Han , Matthew Low , Navin McGinnis , Shufang Su