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Related papers: Deterministic polarization-entanglement purificati…

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We study the use of entanglement purification for quantum communication over long distances. For distances much longer than the coherence length of a corresponding noisy quantum channel, the fidelity of transmission is usually so low that…

Quantum Physics · Physics 2008-12-18 W. Dür , H. - J. Briegel , J. I. Cirac , P. Zoller

We present an entanglement purification protocol for a mixture of a pure entangled state and a pure product state, which are orthogonal to each other. The protocol is combination of bisection method and one-way hashing protocol. We give…

Quantum Physics · Physics 2009-08-06 Mikolaj Czechlewski , Andrzej Grudka , Satoshi Ishizaka , Antoni Wojcik

We suggest and demonstrate a scheme to compensate spatial and spectral decoherence effects in the generation of polarization entangled states by type-I parametric downconversion. In our device a programmable spatial light modulator imposes…

Quantum Physics · Physics 2015-05-19 Simone Cialdi , Davide Brivio , Matteo G A Paris

We give a review on entanglement purification for bipartite and multipartite quantum states, with the main focus on theoretical work carried out by our group in the last couple of years. We discuss entanglement purification in the context…

Quantum Physics · Physics 2009-11-13 W. Dür , H. J. Briegel

The faithful distribution of entanglement over noisy channels is a vital prerequisite for many quantum technological applications. Quantum information can be encoded in different degrees of freedom (DOF) of photons, where each encoding…

Quantum Physics · Physics 2022-03-07 Sebastian Ecker , Philipp Sohr , Lukas Bulla , Rupert Ursin , Martin Bohmann

We experimentally demonstrate that entanglement of bi-photon polarization state can be restored by spectral filters. This restoration procedure can be viewed as a new class of quantum eraser, which retrieves entanglement rather than just…

Quantum Physics · Physics 2007-05-23 K. Usami , Y. Nambu , S. Ishizaka , T. Hiroshima , Y. Tsuda , K. Matsumoto , K. Nakamura

In this paper, we propose a novel bipartite entanglement purification protocol built upon hashing and upon the guessing random additive noise decoding (GRAND) approach recently devised for classical error correction codes. Our protocol…

Quantum Physics · Physics 2024-09-25 André Roque , Diogo Cruz , Francisco A. Monteiro , Bruno C. Coutinho

We introduce a simple, experimentally realisable, entanglement manipulation protocol for exploring mixed state entanglement. We show that for both non-maximally entangled pure, and mixed polarisation-entangled two qubit states, an increase…

Quantum Physics · Physics 2009-11-06 R. T. Thew , W. J. Munro

We present the convergence study of a recurrence entanglement purification protocol using arbitrary two-qubit initial states. The protocol is based on a rank two projector in the Bell basis which serves as a two-qubit operation replacing…

Quantum Physics · Physics 2016-11-23 Juan Mauricio Torres , József Zsolt Bernád

We investigate the purification of entangled states by local actions using a variant of entanglement swapping. We show that there exists a measure of entanglement which is conserved in this type of purification procedure.

Quantum Physics · Physics 2009-10-31 S. Bose , V. Vedral , P. L. Knight

Two qubits in pure entangled states going through separate paths and interacting with their own individual environments will gradually lose their entanglement. Here we show that the entanglement change of a two-qubit state due to amplitude…

Quantum Physics · Physics 2014-01-23 Wei Song , Ming Yang , Zhuo-Liang Cao

In [J. C. Howell and J. A. Yeazell, Phys. Rev. A 62, 012102 (2000)], a proposal is made to generate entangled macroscopically distinguishable states of two spatially separated traveling optical modes. We model the decoherence due to light…

Quantum Physics · Physics 2016-04-26 J. Clausen , L. Knoell , D. -G. Welsch

We present a simple protocol to purify bipartite entanglement in spin-1/2 particles by utilizing only natural spin-spin interactions, i.e. those that can commonly be realized in realistic physical systems, and S_z-measurements on single…

Quantum Physics · Physics 2008-10-23 Koji Maruyama , Franco Nori

Known entanglement purification protocols for mixed states use collective measurements on several copies of the state in order to increase the entanglement of some of them. We address the question of whether it is possible to purify the…

Quantum Physics · Physics 2009-10-31 N. Linden , S. Massar , S. Popescu

Single-photon entanglement is a simple form of entanglement that exists between two spatial modes sharing a single photon. Despite its elementary form, it provides a resource as useful as polarization-entangled photons and it can be used…

As the hyperentanglement of photon systems presents lots of unique opportunities in high-capacity quantum networking, the hyperentanglement purification protocol (hyper-EPP) becomes a vital project work and the quality of its accomplishment…

Quantum Physics · Physics 2018-12-05 Guan-Yu Wang , Tao Li , Qing Ai , Ahmed Alsaedi , Tasawar Hayat , Fu-Guo Deng

An iterative random procedure is considered allowing an entanglement purification of a class of multi-mode quantum states. In certain cases, a complete purification may be achieved using only a single signal state preparation. A physical…

Quantum Physics · Physics 2009-11-10 J Clausen , L Knoell , D-G Welsch

Bipartite entanglement purification is the conversion of copies of weakly entangled pairs shared between two separated parties into a smaller number of strongly entangled shared pairs using only local operations and classical communication.…

Quantum Physics · Physics 2025-11-14 Matthew Barber , Stefano Pirandola

Modeling and simulations of entanglement-based quantum-networking protocols commonly assume perfect entangled states. Some investigations have been performed which show how imperfections cause the efficiency of the protocols to rapidly…

Quantum Physics · Physics 2022-06-28 Randy Lafler , R. Nicholas Lanning

We argue that the entanglement of purification for two dimensional holographic CFT can be obtained from conformal blocks with internal twist operators. First, we explain our formula from the view point of tensor network model of holography.…

High Energy Physics - Theory · Physics 2019-12-06 Hayato Hirai , Kotaro Tamaoka , Tsuyoshi Yokoya