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Related papers: Shared Purity of Multipartite Quantum States

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We argue that a complete characterisation of quantum correlations in bipartite systems of many dimensions may require a quantity which, even for pure states, does not reduce to a single number. Subsequently, we introduce multi-dimensional…

Quantum Physics · Physics 2009-11-07 Piotr Badziag , Piotr Deuar , Michal Horodecki , Pawel Horodecki , Ryszard Horodecki

One spin excitation states are involved in the transmission of quantum states and entanglement through a quantum spin chain, the localization properties of these states are crucial to achieve the transfer of information from one extreme of…

Quantum Physics · Physics 2015-05-14 Analia Zwick , Omar Osenda

Verifying the proper preparation of quantum states is essential in modern quantum information science. Various protocols have been developed to estimate the fidelity of quantum states produced by different parties. Direct fidelity…

Quantum Physics · Physics 2024-12-11 Christopher Vairogs , Bin Yan

Fidelity plays an important role in quantum information theory. In this letter, we introduce new metric of quantum states induced by fidelity, and connect it with the well-known trace metric, Sine metric and Bures metric for the qubit case.…

Quantum Physics · Physics 2015-05-13 Zhihao Ma , Fu-Lin Zhang , Jing-Ling Chen

We demonstrate a multipartite protocol to securely distribute and reconstruct a quantum state. A secret quantum state is encoded into a tripartite entangled state and distributed to three players. Any two of the three players are able to…

Quantum Physics · Physics 2009-11-10 Andrew M. Lance , Thomas Symul , Warwick P. Bowen , Barry C. Sanders , Ping Koy Lam

In this paper we address the problem of optimal reconstruction of a quantum state from the result of a single measurement when the original quantum state is known to be a member of some specified set. A suitable figure of merit for this…

Quantum Physics · Physics 2007-05-23 Kieran Hunter , Erika Andersson , Claire R. Gilson , Stephen M. Barnett

We experimentally prepare a new type of continuous variable genuine four-partite entangled states, the quantum correlation property of which is different from that of the four-mode GHZ and cluster states, and which has not any qubit…

Quantum Physics · Physics 2009-11-13 Aihong Tan , Yu Wang , Xiaoli Jin , Xiaolong Su , Xiaojun Jia , Jing Zhang , Changde Xie , Kunchi Peng

We propose an alternative fidelity measure (namely, a measure of the degree of similarity) between quantum states and benchmark it against a number of properties of the standard Uhlmann-Jozsa fidelity. This measure is a simple function of…

Characterizing and quantifying quantum correlations in states of many-particle systems is at the core of a full understanding of phase transitions in matter. In this work, we continue our investigation of the notion of generalized…

Quantum Physics · Physics 2009-11-10 Rolando Somma , Gerardo Ortiz , Howard Barnum , Emanuel Knill , Lorenza Viola

We examine the physical significance of fidelity as a measure of similarity for Gaussian states, by drawing a comparison with its classical counterpart. We find that the relationship between these classical and quantum fidelities is not…

Quantum Physics · Physics 2015-06-26 H. Jeong , T. C. Ralph , W. P. Bowen

General semiclassical expression for quantum fidelity (Loschmidt echo) of arbitrary pure and mixed states is derived. It expresses fidelity as an interference sum of dephasing trajectories weighed by the Wigner function of the initial…

Quantum Physics · Physics 2007-05-23 Jiri Vanicek

Self-testing refers to the certification of quantum states and measurements based entirely on the correlations exhibited by measurements on separate subsystems. In the bipartite case, self-testing of states has been completely…

We derive a computable analytical formula for the quantum fidelity between two arbitrary multimode Gaussian states which is simply expressed in terms of their first- and second-order statistical moments. We also show how such a formula can…

Quantum Physics · Physics 2015-12-23 Leonardo Banchi , Samuel L. Braunstein , Stefano Pirandola

We study the separability of symmetric bipartite quantum states and show that a single correlation measurement is sufficient to detect the entanglement of any bipartite symmetric state with a non-positive partial transpose. We also discuss…

Quantum Physics · Physics 2010-02-24 Geza Toth , Otfried Gühne

Quantum discord, an information-theoretic quantum correlation measure, can satisfy as well as violate monogamy, for three-party quantum states. We quantify the feature using the concept of discord monogamy score. We find a necessary…

Quantum Physics · Physics 2014-04-21 Manabendra N. Bera , R. Prabhu , Aditi Sen De , Ujjwal Sen

We present two measures of distance between quantum processes based on the superfidelity, introduced recently to provide an upper bound for quantum fidelity. We show that the introduced measures partially fulfill the requirements for…

Quantum Physics · Physics 2011-01-26 Zbigniew Puchała , Jarosław Adam Miszczak , Piotr Gawron , Bartłomiej Gardas

We introduce a complete set of complementary quantities in bipartite, two-dimensional systems. Complementarity then relates the quantitative entanglement measure concurrence which is a bipartite property to the single-particle quantum…

Quantum Physics · Physics 2007-05-23 Matthias Jakob , Janos A. Bergou

We experimentally address the significance of fidelity as a figure of merit in quantum state reconstruction of discrete (DV) and continuous variable (CV) quantum optical systems. In particular, we analyze the use of fidelity in quantum…

In recent years, several measures have been proposed for characterizing the coherence of a given quantum state. We derive several results that illuminate how these measures behave when restricted to pure states. Notably, we present an…

Quantum Physics · Physics 2016-10-26 Jianxin Chen , Shane Grogan , Nathaniel Johnston , Chi-Kwong Li , Sarah Plosker

The concept of entanglement and separability of quantum states is relevant for several fields in physics. Still, there is a lack of effective operational methods to characterise these features. We propose a method to certify quantum…

Quantum Physics · Physics 2024-03-06 Ties-A. Ohst , Xiao-Dong Yu , Otfried Gühne , H. Chau Nguyen