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We present a new method of analytically deriving the entanglement of formation of the bipartite mixed state. The method realizes the optimal decomposition families of states. Our method can lead to many new results concerning entanglement…

Quantum Physics · Physics 2007-10-16 Lin Chen , Yi-Xin Chen

Given a bipartite quantum state (in arbitrary dimension) and a decomposition of it as a superposition of two others, we find bounds on the entanglement of the superposition state in terms of the entanglement of the states being superposed.…

Quantum Physics · Physics 2009-11-11 Noah Linden , Sandu Popescu , John A. Smolin

We explore the dynamics of two atoms interacting with a cavity field via deformed operators. Properties of the asymptotic regularization of entanglement measures proving, for example, purity cost, regularized fidelity and accuracy of…

Quantum Physics · Physics 2015-05-18 N. Metwally , M. Sebawe Abdalla , M. Abdel-Aty

In this paper, the following scenario is considered: there are two qubits possessed by two parties at different locations. Qubits have been prepared in one of a maximum of four, mutually-orthogonal, entangled states and the parties wish to…

Quantum Physics · Physics 2016-09-29 Özenç Güngör , Sadi Turgut

We provide generalizations of known two-qubit entanglement distillation protocols for arbitrary Hilbert space dimensions. The protocols, which are analogues of the hashing and breeding procedures, are adapted to bipartite quantum states…

Quantum Physics · Physics 2009-11-07 K. G. H. Vollbrecht , M. M. Wolf

Entanglement is the central resource of quantum information processing and the precise characterization of entangled states is a crucial issue for the development of quantum technologies. This leads to the necessity of a precise,…

Sharing genuine multipartite entanglement by considering collective use of copies of biseparable states, which are entangled across all bipartitions but lack genuine multipartite entanglement at the single-copy level, plays a central role…

Quantum Physics · Physics 2026-01-26 Swati Choudhary , Ujjwal Sen , Saronath Halder

This paper presents an efficient method for detecting entanglement in high-dimensional two-qudit states by mapping the Hilbert space onto the space of two qubits. This transformation enables the use of well-established two-qubit…

Quantum Physics · Physics 2026-02-25 Josef Kadlec , Artur Barasiński , Karel Lemr

Careful tailoring the quantum state of probes offers the capability of investigating matter at unprecedented precisions. Rarely, however, the interaction with the sample is fully encompassed by a single parameter, and the information…

Two-qubit states occupy a large and relatively unexplored Hilbert space. Such states can be succinctly characterized by their degree of entanglement and purity. In this letter we investigate entangled mixed states and present a class of…

Quantum Physics · Physics 2009-11-07 W. J. Munro , D. F. V. James , A. G. White , P. G. Kwiat

Entanglement concurrence has been widely used for featuring entanglement in quantum experiments. As an entanglement monotone it is related to specific quantum Tsallis entropy. Our goal in this paper is to propose a new parameterized…

Quantum Physics · Physics 2021-05-26 Xue Yang , Ming-Xing Luo , Yan-Han Yang , Shao-Ming Fei

We introduce a class of quantum channels with correlations acting on pairs of qubits, where the correlation takes the form of a shift operator onto a maximally entangled state. We optimise the output purity and show that below a certain…

Quantum Physics · Physics 2008-05-19 Filippo Caruso , Vittorio Giovannetti , Chiara Macchiavello , Mary Beth Ruskai

The problem of the reliable transfer of entanglement from one pure bipartite quantum state to another using local operations is analyzed. It is shown that in the case of qubits the amount that can be transferred is restricted to the…

Quantum Physics · Physics 2007-05-23 Berry Groisman

We address the experimental determination of entanglement for systems made of a pair of polarization qubits. We exploit quantum estimation theory to derive optimal estimators, which are then implemented to achieve ultimate bound to…

Quantum Physics · Physics 2015-05-27 G. Brida , I. P. Degiovanni , A. Florio , M. Genovese , P. Giorda , A. Meda , M. G. A. Paris , A. Shurupov

We describe an entanglement purification protocol to generate maximally entangled states with high efficiencies from two-mode squeezed states or from mixed Gaussian continuous entangled states. The protocol relies on a local quantum…

Quantum Physics · Physics 2009-10-31 Lu-Ming Duan , G. Giedke , J. I. Cirac , P. Zoller

We examine two conditions that can be used to detect bipartite entanglement, and show that they can be used to provide lower bounds on the negativity of states. We begin with two-qubit states, and then show how what was done there can be…

Quantum Physics · Physics 2024-02-14 Mark Hillery , Camilla Polvara , Vadim Oganesyan , Nada Ali

We propose an entanglement purification scheme based on material qubits and ancillary coherent multiphoton states. We consider a typical QED scenario where material qubits implemented by two-level atoms fly sequentially through a cavity and…

Quantum Physics · Physics 2016-03-14 József Zsolt Bernád , Juan Mauricio Torres , Ludwig Kunz , Gernot Alber

If we want to transform the quantum state of a system to another using local measurement processes, what is the probability of success? This probability is bounded by quantifying entanglement in both the states. In this paper, we construct…

Quantum Physics · Physics 2026-03-18 Abhijit Gadde , Shraiyance Jain , Harshal Kulkarni

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

Quantum secret sharing is one of the most important and interesting quantum information processing task. In quantum secret sharing, information is split among several parties such that only one of them is able to recover the qubit exactly…

Quantum Physics · Physics 2010-11-15 Satyabrata Adhikari