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Related papers: Mixedness and teleportation

200 papers

The bounds on concurrence of the superposition state in terms of those of the states being superposed are studied in this paper. The bounds on concurrence are quite different from those on the entanglement measure based on von Neumann…

Quantum Physics · Physics 2009-11-13 Chang-shui Yu , X. X. Yi , He-shan Song

The positive partial transpose test is one of the main criteria for detecting entanglement, and the set of states with positive partial transpose is considered as an approximation of the set of separable states. However, we do not know to…

Quantum Physics · Physics 2015-05-13 Salman Beigi , Peter W. Shor

Quantum teleportation of qudits is revisited. In particular, we analyze the case where the quantum channel corresponds to a non-maximally entangled state and show that the success of the protocol is directly related to the problem of…

Quantum Physics · Physics 2009-11-10 L. Roa , A. Delgado , I. Fuentes-Guridi

In quantum information theory, von Neumann entropy plays an important role. The entropies can be obtained analytically only for a few states. In continuous variable system, even evaluating entropy numerically is not an easy task since the…

Quantum Physics · Physics 2015-05-13 Xiao-yu Chen

The ability of entangled states to act as resource for teleportation is linked to a property of the fully entangled fraction. We show that the set of states with their fully entangled fraction bounded by a threshold value required for…

Quantum Physics · Physics 2015-05-30 Nirman Ganguly , Satyabrata Adhikari , A. S. Majumdar , Jyotishman Chatterjee

The dynamics of maximum entangled coherent state travels through an amplitude damping channel is investigated. For small values of the transmissivity rate the travelling state is very fragile to this noise channel, where it suffers from the…

Quantum Physics · Physics 2012-02-21 A. El Allati , Y. Hassouni , N. Metwally

We consider mixed states of two qubits and show under which global unitary operations their entanglement is maximized. This leads to a class of states that is a generalization of the Bell states. Three measures of entanglement are…

Quantum Physics · Physics 2009-11-06 Frank Verstraete , Koenraad Audenaert , Tijl De Bie , Bart De Moor

We find that quantum teleportation, using the thermally entangled state of two-qubit Heisenberg XX chain as a resource, with fidelity better than any classical communication protocol is possible. However, a thermal state with a greater…

Quantum Physics · Physics 2009-11-07 Ye Yeo

This paper explores the fundamental relationship between the geometry of entanglement and von Neumann entropy, shedding light on the intricate nature of quantum correlations. We provide a comprehensive overview of entanglement, highlighting…

Quantum Physics · Physics 2024-06-03 Ramita Sarkar , Soumik Mahanti , Prasanta K. Panigrahi

The decay of a parent particle into two or more daughter particles results in an entangled quantum state as a consequence of conservation laws in the decay process. Recent experiments at Belle and BaBar take advantage of quantum…

High Energy Physics - Theory · Physics 2013-11-25 Louis Lello , Daniel Boyanovsky , Richard Holman

We prove an area law for the entanglement entropy in gapped one dimensional quantum systems. The bound on the entropy grows surprisingly rapidly with the correlation length; we discuss this in terms of properties of quantum expanders and…

Quantum Physics · Physics 2018-07-12 M. B. Hastings

Previously proposed measures of entanglement, such as entanglement of formation and assistance, are shown to be special cases of the relative entropy of entanglement. The difference between these measures for an ensemble of mixed states is…

Quantum Physics · Physics 2009-10-31 L. Henderson , V. Vedral

We propose a mixedness quantifier based on entropy fluctuations. It provides information about the degree of mixedness either for finite dimensional and infinite dimensional Hilbert spaces. It may be used to determine the reduction of the…

Quantum Physics · Physics 2019-07-18 Jorge A. Anaya-Contreras , Arturo Zúñiga-Segundo , Héctor M. Moya-Cessa

Using the concept of von Neumann entropy, we quantify the information content of the various components of the quantum walk system, including the mutual information between its subsystems (coin and position) and use it to give a precise…

Mathematical Physics · Physics 2011-10-11 Clement Ampadu

We use photon pairs hyperentangled in polarization and orbital angular momentum to implement a novel entanglement-enhanced quantum state communication technique, known as SuperDense Teleportation, to communicate a specific class of…

Quantum Physics · Physics 2019-06-26 Trent M. Graham , Herbert J. Bernstein , Tzu-Chieh Wei , Marius Junge , Paul G. Kwiat

We show that a von Neumann measurement on a part of a composite quantum system unavoidably creates distillable entanglement between the measurement apparatus and the system if the state has nonzero quantum discord. The minimal distillable…

Quantum Physics · Physics 2011-05-03 Alexander Streltsov , Hermann Kampermann , Dagmar Bruß

The ability to distribute quantum entanglement is a prerequisite for many fundamental tests of quantum theory and numerous quantum information protocols. Two distant parties can increase the amount of entanglement between them by means of…

Quantum Physics · Physics 2012-08-24 T. K. Chuan , J. Maillard , K. Modi , T. Paterek , M. Paternostro , M. Piani

We propose a generalized form of optimal teleportation witness to demonstrate their importance in experimental detection of the larger set of entangled states useful for teleportation in higher dimensional systems. The interesting…

Quantum Physics · Physics 2015-05-11 Atul Kumar , Satyabrata Adhikari , Pankaj Agrawal

The precise quantification of the ultimate efficiency in manipulating quantum resources lies at the core of quantum information theory. However, purely information-theoretic measures fail to capture the actual computational complexity…

Quantum Physics · Physics 2025-11-19 Lorenzo Leone , Jacopo Rizzo , Jens Eisert , Sofiene Jerbi

When a superposition $(|\alpha>-|-\alpha>)$ of two coherent states with opposite phase falls upon a 50-50 beamsplitter, the resulting state is entangled. Remarkably, the amount of entanglement is exactly 1 ebit, irrespective of $\alpha$, as…

Quantum Physics · Physics 2009-11-06 S. J. van Enk , O. Hirota