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Related papers: Assisted state discrimination without entanglement

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We introduce a new family of separability criteria that are based on the existence of extensions of a bipartite quantum state $\rho$ to a larger number of parties satisfying certain symmetry properties. It can be easily shown that all…

Quantum Physics · Physics 2007-05-23 Andrew C. Doherty , Pablo A. Parrilo , Federico M. Spedalieri

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

In this paper we present a necessary and sufficient condition of distinguishability of bipartite quantum states. It is shown that the operators to reliably distinguish states need only rounds of projective measurements and classical…

Quantum Physics · Physics 2016-09-08 Ping-Xing Chen , Cheng-Zu Li

We present a set of inequalities for detecting quantum entanglement of $2\otimes d$ quantum states. For $2\otimes 2$ and $2\otimes 3$ systems, the inequalities give rise to sufficient and necessary separability conditions for both pure and…

Quantum Physics · Physics 2011-05-25 Ming-Jing Zhao , Teng Ma , Shao-Ming Fei , Zhi-Xi Wang

We construct a set of PPT (positive partial transpose) states and show that these PPT states are not separable, thus present a class of bound entangled quantum states.

Quantum Physics · Physics 2009-11-13 Shao-Ming Fei , Xianqing Li-Jost , Bao-Zhi Sun

It is shown that local distinguishability of orthogonal mixed states can be completely characterized by local distinguishability of their supports irrespective of entanglement and mixedness of the states. This leads to two kinds of upper…

Quantum Physics · Physics 2012-04-20 Somshubhro Bandyopadhyay

In this Letter, we show that the fulfillment of uncertainty relations is a sufficient criterion for a quantum-mechanically permissible state. We specifically construct two pseudo-spin observables for an arbitrary non-positive Hermitian…

Quantum Physics · Physics 2009-11-13 Hyunchul Nha , M. Suhail Zubairy

Quantum discord quantifies non-classical correlations in a quantum system including those not captured by entanglement. Thus, only states with zero discord exhibit strictly classical correlations. We prove that these states are negligible…

Quantum Physics · Physics 2015-05-14 A. Ferraro , L. Aolita , D. Cavalcanti , F. M. Cucchietti , A. Acin

The equivalence between absolutely separable states and absolutely positive partial transposed (PPT) states in general remains an open problem in quantum entanglement theory. In this work, we study an analogous question for symmetric…

Quantum Physics · Physics 2025-04-16 Jonathan Louvet , Eduardo Serrano-Ensástiga , Thierry Bastin , John Martin

Quantum state discrimination is one of the most fundamental problems studied in quantum information theory. Applications range from channel coding to metrology and cryptography. In this work, we introduce a new variant of this task: Local…

Quantum Physics · Physics 2024-05-20 Christian Majenz , Maris Ozols , Christian Schaffner , Mehrdad Tahmasbi

The separability of bipartite non-Gaussian states is studied by applying the realignment criterion with the technique of functional analysis. The realignment criterion is given as one inequality in contrast to the infinitive number of…

Quantum Physics · Physics 2014-02-05 Xiao-yu Chen , Li-zhen Jiang , Ping Yu , Mingzhen Tian

Entanglement is a central feature of quantum theory. Mathematical properties and physical applications of pure state entanglement make it a template to study quantum correlations. However, an extension of entanglement measures to mixed…

Quantum Physics · Physics 2017-07-19 Aharon Brodutch , Daniel R. Terno

Deterministic discrimination of nonorthogonal states is forbidden by quantum measurement theory. However, if we do not want to succeed all the time, i.e. allow for inconclusive outcomes to occur, then unambiguous discrimination becomes…

Quantum Physics · Physics 2009-11-11 Janos Bergou , Ulrike Herzog , Mark Hillery

We develop a strong and computationally simple entanglement criterion. The criterion is based on an elementary positive map Phi which operates on state spaces with even dimension N >= 4. It is shown that Phi detects many entangled states…

Quantum Physics · Physics 2007-05-23 Heinz-Peter Breuer

We address the problem of unambiguous discrimination among a given set of quantum operations. The necessary and sufficient condition for them to be unambiguously distinguishable is derived in the cases of single use and multiple uses…

Quantum Physics · Physics 2009-11-11 Guoming Wang , Mingsheng Ying

We present a novel approach to the separability problem for Gaussian quantum states of bosonic continuous variable systems. We derive a simplified necessary and sufficient separability criterion for arbitrary Gaussian states of $m$ vs $n$…

Quantum Physics · Physics 2018-02-22 Ludovico Lami , Alessio Serafini , Gerardo Adesso

It is known that unambiguous discrimination among non-orthogonal but linearly independent quantum states is possible with a certain probability of success. Here, we consider a variant of that problem. Instead of discriminating among all of…

Quantum Physics · Physics 2009-11-07 Yuqing Sun , Janos A. Bergou , Mark Hillery

Quantum discord quantifies quantum correlation between quantum systems, which has potential application in quantum information processing. In this paper, we propose a scheme realizing the remote transfer of Gaussian quantum discord, in…

Quantum Physics · Physics 2023-07-19 Lingyu Ma , Xiaolong Su

Nonorthogonal quantum state discrimination (QSD) plays an important role in quantum information and quantum communication. In addition, compared to Hermitian quantum systems, parity-time-($\mathcal{PT}$-)symmetric non-Hermitian quantum…

Quantum Physics · Physics 2022-09-07 Dong-Xu Chen , Yu Zhang , Jun-Long Zhao , Qi-Cheng Wu , Yu-Liang Fang , Chui-Ping Yang , Franco Nori

We study discrimination of m quantum measurements in the scenario when the unknown measurement with n outcomes can be used only once. We show that ancilla-assisted discrimination procedures provide a nontrivial advantage over simple…

Quantum Physics · Physics 2014-12-01 Michal Sedlak , Mario Ziman