Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:0812.3255 · Physical Review Letters

Local Transformation of Two Einstein-Podolsky-Rosen Photon Pairs into a Three-Photon W State

Toshiyuki Tashima, T. Wakatsuki, Şahin Kaya Özdemir, Takashi Yamamoto, Masato Koashi, Nobuyuki Imoto

Published Apr 3, 2009• 104 citations
arXivHTMLPDF

Abstract

We propose and experimentally demonstrate a transformation of two Einstein-Podolsky-Rosen photon pairs distributed among three parties into a three-photon W state using local operations and classical communication. We then characterize the final state using quantum state tomography on the three-photon state and on its marginal bipartite states. The fidelity of the final state to the ideal W state is 0.778+/-0.043 and the expectation value for its witness operator is -0.111+/-0.043 implying the success of the proposed local transformation.

DOI
10.1103/physrevlett.102.130502

Related papers

Local transformation of two EPR photon pairs into a three-photon W state

Toshiyuki Tashima, T. Wakatsuki, Şahin Kaya Özdemir +4 more

We propose and demonstrate a local transformation of two EPR photon pairs to three‐photon W state. The key issue of our scheme is that it requires only one polarization dependent beamsplitter to perform the necessary local operation. Using a quantum state tomography, the fidelity of the prepared three‐photon state was estimated as 0.778±0.043. The expectation value of the witness operator of W3 was −0.111±0.043.

AIP conference proceedings•Jan 1, 2009•3 citations

Local conversion of four Einstein-Podolsky-Rosen photon pairs into four-photon polarization-entangled decoherence-free states with non-photon-number-resolving detectors

Hong‐Fu Wang, Shou Zhang, Ai‐Dong Zhu +2 more

We propose a linear-optics-based scheme for local conversion of four Einstein-Podolsky-Rosen photon pairs distributed among five parties into four-photon polarization-entangled decoherence-free states using local operations and classical communication. The proposed setup involves simple linear optical elements and non-photon-number-resolving detectors that can only distinguish between the presence and absence of photons, and no information on the exact number of photons can be obtained. This greatly simplifies the experimental realization for linear optical quantum computation and quantum information processing.

Optics Express•Nov 29, 2011•24 citations

Preparation of a three-photon W state from two EPR photon pairs by LOCC

Toshiyuki Tashima, T. Wakatsuki, S. K. Ozdemi +3 more

In quantum information science, it is often the question what distantly located parties sharing EPR pairs can achieve if they are restricted to only local operations and classical communication (LOCC). State preparation and transformation is one of such tasks, which have been attracted considerable interest since the early years of the field. It is well-known that starting with EPR pairs, any two-qubit pure state can be prepared via only LOCC. Thus EPR pairs form a universal resource. However, the situation is very different when the multipartite entanglement is considered, because in multipartite entanglement, there are distinct classes of entanglement, which cannot be converted into each other with unit fidelity even under stochastic local operation and classical communication (SLOCC), e.g., two distinct classes of states, GHZ-type and W-type states for the tripartite cases [1]. There exists no tripartite state that can be used as a universal resource to generate arbitrary tripartite pure states using SLOCC. For this purpose, one must look for a resource in larger systems such as many shared EPR pairs to extract the desired multipartite state. For example, there is a direct way of converting two EPR pairs into a three-qubit GHZ-type state [2], which then can be used to prepare approximate W state [3]. In this conversion from GHZ to W state, there is a trade-off between the fidelity and success probability. Unit fidelity cannot be achieved with non-zero probability, which confirms that GHZ- and W-type states belong to distinct classes.

Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)•Jun 1, 2009•0 citations

Communication via one- and two-particle operators on Einstein-Podolsky-Rosen states

Charles H. Bennett, Stephen J. Wiesner

As is well known, operations on one particle of an Einstein-Podolsky-Rosen (EPR) pair cannot influence the marginal statistics of measurements on the other particle. We characterize the set of states accessible from an initial EPR state by one-particle operations and show that in a sense they allow two bits to be encoded reliably in one spin-1/2 particle: One party, ``Alice,'' prepares an EPR pair and sends one of the particles to another party, ``Bob,'' who applies one of four unitary operators to the particle, and then returns it to Alice. By measuring the two particles jointly, Alice can now reliably learn which operator Bob used.

Physical Review Letters•Nov 16, 1992•5,452 citations

Local Conversion of Greenberger-Horne-Zeilinger States to Approximate W States

Philip John Walther, Kevin J. Resch, Anton Zeilinger

Genuine 3-qubit entanglement comes in two different inconvertible types represented by the Greenberger-Horne-Zeilinger (GHZ) state and the $W$ state. We describe a specific method based on local positive operator valued measures and classical communication that can convert the ideal $N$-qubit GHZ state to a state arbitrarily close to the ideal $N$-qubit $W$ state. We then experimentally implement this scheme in the 3-qubit case and characterize the input and the final state using 3-photon quantum state tomography.

arXiv:quant-ph/0506190•Physical Review Letters•Jun 22, 2005•80 citations

Efficient generation of multi-photon W states by joint-measurement

Wenhu Xu, Xin Zhao, Guilu Long

We propose an efficient scheme to generate multi-photon entangled W state from two-qubit Einstein–Podolsky–Rosen pairs by measurements and follow-up local transformation. We discuss the efficiency of the scheme under realistic conditions, and its implementation using current technology.

Progress in Natural Science Materials International•Dec 6, 2007•11 citations
We propose and experimentally demonstrate a transformation of two Einstein-Podolsky-Rosen photon pairs distributed among three parties into a three-photon W state using local operations and classical communication. We then characterize the final state using quantum state tomography on the three-photon state and on its marginal bipartite states. The fidelity of the final state to the ideal W state is 0.778+/-0.043 and the expectation value for its witness operator is -0.111+/-0.043 implying the success of the proposed local transformation.
We propose a linear-optics-based scheme for local conversion of four Einstein-Podolsky-Rosen photon pairs distributed among five parties into four-photon polarization-entangled decoherence-free states using local operations and classical communication. The proposed setup involves simple linear optical elements and non-photon-number-resolving detectors that can only distinguish between the presence and absence of photons, and no information on the exact number of photons can be obtained. This greatly simplifies the experimental realization for linear optical quantum computation and quantum information processing.
In quantum information science, it is often the question what distantly located parties sharing EPR pairs can achieve if they are restricted to only local operations and classical communication (LOCC). State preparation and transformation is one of such tasks, which have been attracted considerable interest since the early years of the field. It is well-known that starting with EPR pairs, any two-qubit pure state can be prepared via only LOCC. Thus EPR pairs form a universal resource. However, the situation is very different when the multipartite entanglement is considered, because in multipartite entanglement, there are distinct classes of entanglement, which cannot be converted into each other with unit fidelity even under stochastic local operation and classical communication (SLOCC), e.g., two distinct classes of states, GHZ-type and W-type states for the tripartite cases [1]. There exists no tripartite state that can be used as a universal resource to generate arbitrary tripartite pure states using SLOCC. For this purpose, one must look for a resource in larger systems such as many shared EPR pairs to extract the desired multipartite state. For example, there is a direct way of converting two EPR pairs into a three-qubit GHZ-type state [2], which then can be used to prepare approximate W state [3]. In this conversion from GHZ to W state, there is a trade-off between the fidelity and success probability. Unit fidelity cannot be achieved with non-zero probability, which confirms that GHZ- and W-type states belong to distinct classes.
As is well known, operations on one particle of an Einstein-Podolsky-Rosen (EPR) pair cannot influence the marginal statistics of measurements on the other particle. We characterize the set of states accessible from an initial EPR state by one-particle operations and show that in a sense they allow two bits to be encoded reliably in one spin-1/2 particle: One party, ``Alice,'' prepares an EPR pair and sends one of the particles to another party, ``Bob,'' who applies one of four unitary operators to the particle, and then returns it to Alice. By measuring the two particles jointly, Alice can now reliably learn which operator Bob used.
Genuine 3-qubit entanglement comes in two different inconvertible types represented by the Greenberger-Horne-Zeilinger (GHZ) state and the WWW state. We describe a specific method based on local positive operator valued measures and classical communication that can convert the ideal NNN-qubit GHZ state to a state arbitrarily close to the ideal NNN-qubit WWW state. We then experimentally implement this scheme in the 3-qubit case and characterize the input and the final state using 3-photon quantum state tomography.