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Nonlocal unitary operations can create quantum entanglement between distributed particles, and the quantification of created entanglement is a hard problem. It corresponds to the concepts of entangling and assisted entangling power when the…

Quantum Physics · Physics 2016-10-27 Lin Chen , Li Yu

We study the remote implementation of a unitary transformation on a qubit. We show the existence of non-trivial protocols (i.e., using less resources than bidirectional state teleportation) which allow the perfect remote implementation of…

Quantum Physics · Physics 2009-11-07 S. F. Huelga , M. B. Plenio , J. A. Vaccaro

A necessary and sufficient condition of the possibility of a deterministic local operations and classical communication (LOCC) transformation of three-qubit pure states is given. The condition shows that the three-qubit pure states are a…

Quantum Physics · Physics 2015-05-20 Hiroyasu Tajima

Understanding entanglement cost in non-local quantum computation (NLQC) is relevant to complexity, cryptography, gravity, and other areas. This entanglement cost is largely uncharacterized; previous lower bound techniques apply to narrowly…

Quantum Physics · Physics 2026-05-01 Richard Cleve , Alex May

The problem behind this paper is, if the number of queries to unitary operations is fixed, say $k$, then when do local operations and classical communication (LOCC) suffice for optimally distinguishing bipartite unitary operations? We…

Quantum Physics · Physics 2017-12-06 Lvzhou Li , Shenggen Zheng , Haozhen Situ , Daowen Qiu

Establishing a fully functional quantum internet relies on the efficient allocation of multipartite entangled states, which enables advanced quantum communication protocols, secure multipartite quantum key distribution, and distributed…

Quantum Physics · Physics 2024-09-26 Yu-Ao Chen , Xia Liu , Chenghong Zhu , Lei Zhang , Junyu Liu , Xin Wang

This is a book-length treatment of the subject of non-local quantum computation (NLQC). NLQC is a method for implementing quantum operations that interact two systems without directly bringing the systems together. Instead, a single round…

Quantum Physics · Physics 2026-05-05 Alex May

Operator entanglement of two-qubit joint unitary operations is revisited. Schmidt number is an important attribute of a two-qubit unitary operation, and may have connection with the entanglement measure of the unitary operator. We found the…

Quantum Physics · Physics 2015-06-04 Hui-Zhi Xia , Chao Li , Qing Yang , Ming Yang , Zhuo-Liang Cao

We prove that the entanglement cost equals the regularized entanglement of formation for any infinite-dimensional quantum state $\rho_{AB}$ with finite quantum entropy on at least one of the subsystems $A$ or $B$. This generalizes a…

Quantum Physics · Physics 2026-05-26 Hayata Yamasaki , Kohdai Kuroiwa , Patrick Hayden , Ludovico Lami

Entanglement bits or ``ebits'' have been proposed as a quantitative measure of a fundamental resource in quantum information processing. For such an interpretation to be valid, it is important to show that the same number of ebits in…

Quantum Physics · Physics 2009-10-31 Hoi-Kwong Lo , Sandu Popescu

Understanding multipartite entanglement is vital, as it underpins a wide range of phenomena across physics. The study of transformations of states via Local Operations assisted by Classical Communication (LOCC) allows one to quantitatively…

Quantum Physics · Physics 2021-09-01 Antoine Neven , David Gunn , Martin Hebenstreit , Barbara Kraus

A general method for implementing weakly entangling multipartite unitary operations using a small amount of entanglement and classical communication is presented. For the simple Hamiltonian \sigma_z\otimes\sigma_z this method requires less…

Quantum Physics · Physics 2007-05-23 Dominic W. Berry

We consider a single copy of a mixed state of two qubits and derive the optimal trace-preserving local operations assisted by classical communication (LOCC) such as to maximize the fidelity of teleportation that can be achieved with this…

Quantum Physics · Physics 2009-11-10 F. Verstraete , H. Verschelde

We consider a two-qubit unitary operation along with arbitrary local unitary operations acts on a two-qubit pure state, whose entanglement is C_0. We give the conditions that the final state can be maximally entangled and be non-entangled.…

Quantum Physics · Physics 2009-11-10 M. -Y. Ye , Dong Sun , Y. -S. Zhang , G. -C. Guo

We consider generic pure $n$-qubit states and a general class of pure states of arbitrary dimensions and arbitrarily many subsystems. We characterize those states which can be reached from some other state via Local Operations assisted by…

Quantum Physics · Physics 2017-02-01 C. Spee , J. I. de Vicente , D. Sauerwein , B. Kraus

In order to cope with the fact that there exists no single maximally entangled state (up to local unitaries) in the multipartite setting, we introduced in [J. I. de Vicente, C. Spee and B. Kraus, Phys. Rev. Lett. 111, 110502 (2013)] the…

Quantum Physics · Physics 2016-12-14 C. Spee , J. I. de Vicente , B. Kraus

We show how shared entanglement, together with classical communication and local quantum operations, can be used to perform an arbitrary collective quantum operation upon N spatially-separated qubits. A simple teleportation-based protocol…

Quantum Physics · Physics 2009-11-06 Anthony Chefles , Claire R. Gilson , Stephen M. Barnett

We investigate how originally localized two pieces of quantum information represented by a tensor product of two unknown qudit states are delocalized by performing two-qudit global unitary operations. To characterize the delocalization…

Quantum Physics · Physics 2010-09-15 Akihito Soeda , Mio Murao

We introduce two operational entanglement measures which are applicable for arbitrary multipartite (pure or mixed) states. One of them characterizes the potentiality of a state to generate other states via local operations assisted by…

Quantum Physics · Physics 2015-10-14 K. Schwaiger , D. Sauerwein , M. Cuquet , J. I. de Vicente , B. Kraus

Entangled states can help in quantum state discrimination by local operations and classical communication (LOCC). For example, a Bell state is necessary (and sufficient) to perfectly discriminate a set of either three or four Bell states by…

Quantum Physics · Physics 2021-10-04 Somshubhro Bandyopadhyay , Vincent Russo