English
Related papers

Related papers: Local channels preserving maximal entanglement or …

200 papers

Entanglement and entanglement-assisted are useful resources to enhance the mutual information of the Pauli channels, when the noise on consecutive uses of the channel has some partial correlations. In this Paper, we study…

Quantum Physics · Physics 2015-06-26 A. Fahmi , M. Golshani

In the quantum system, perfect copying is impossible without prior knowledge. But, perfect copying is possible, if it is known that unknown states to be copied is contained by the set of orthogonal states, which is called the copied set.…

Quantum Physics · Physics 2007-05-23 Masaki Owari , Masahito Hayashi

We explicitly exhibit a set of four ququad-ququad orthogonal maximally entangled states that cannot be perfectly distinguished by means of local operations and classical communication. Before our work, it was unknown whether there is a set…

Quantum Physics · Physics 2013-09-24 Nengkun Yu , Runyao Duan , Mingsheng Ying

Every Maximally Entangled State (MES) of two d-dimensional particles is shown to be a product state of suitably chosen collective coordinates. The state may be viewed as defining a "point" in a "phase space" like d^2 array representing d^2…

Quantum Physics · Physics 2016-11-26 M. Revzen

Entanglement plays a central role in the field of quantum information science. It is well known that the degree of entanglement cannot be increased under local operations. Here, we show that the concurrence of a bipartite entangled state…

Quantum Physics · Physics 2014-12-25 Shin-Liang Chen , Guang-Yin Chen , Yueh-Nan Chen

We consider systems of interacting spins and study the entanglement that can be localized, on average, between two separated spins by performing local measurements on the remaining spins. This concept of Localizable Entanglement (LE) leads…

Quantum Physics · Physics 2007-05-23 M. Popp , F. Verstraete , M. A. Martin-Delgado , J. I. Cirac

We consider explicitly two examples of d-dimensional quantum channels with correlated noise and show that, in agreement with previous results on Pauli qubit channels, there are situations where maximally entangled input states achieve…

Quantum Physics · Physics 2007-05-23 E. Karpov , D. Daems , N. J. Cerf

Ask how the quantum compression of ensembles of pure states is affected by the availability of entanglement, and in settings where the encoder has access to side information. We find the optimal asymptotic quantum rate and the optimal…

Quantum Physics · Physics 2020-05-22 Zahra Baghali Khanian , Andreas Winter

It is well known that the quantum mutual information and its conditional version do not increase under local channels. I this paper we show that the recently established lower semicontinuity of the quantum conditional mutual information…

Quantum Physics · Physics 2021-09-28 M. E. Shirokov

We study the capacity of d-dimensional quantum channels with memory modeled by correlated noise. We show that, in agreement with previous results on Pauli qubit channels, there are situations where maximally entangled input states achieve…

Quantum Physics · Physics 2007-05-23 E. Karpov , D. Daems , N. J. Cerf

There is an ongoing effort to quantify entanglement of quantum pure states for systems with more than two subsystems. We consider three approaches to this problem for three-qubit states: choosing a basis which puts the state into a standard…

Quantum Physics · Physics 2009-11-06 Todd A. Brun , Oliver Cohen

Classical entanglement refers to non-separable correlations between the polarization direction and the polarization amplitude of a light field. The degree of entanglement is quantified by the Schmidt number, taking the value of unity for a…

Quantum Physics · Physics 2023-07-19 Ziyang You , Zikang Tang , Hou Ian

Superselection rules severely alter the possible operations that can be implemented on a distributed quantum system. Whereas the restriction to local operations imposed by a bipartite setting gives rise to the notion of entanglement as a…

Quantum Physics · Physics 2009-11-10 N. Schuch , F. Verstraete , J. I. Cirac

We first present a generalized criterion for maximally entangled states of 2, 3, 4, 5, 6, 8 and in theory to arbitrary-number qubits. By this criterion, some known highly entangled multi-qubit states are examined and a new genuine…

Quantum Physics · Physics 2015-06-04 Xinwei Zha , Chenzhi Yuan , Yanpeng Zhang

In quantum information theory, the reliable and effective detection of entanglement is of paramount importance. However, given an unknown state, assessing its entanglement is a challenging task. To attack this problem, we investigate the…

Quantum Physics · Physics 2015-12-09 Jochen Szangolies , Hermann Kampermann , Dagmar Bruß

Unlike the entanglement of quantum states, very little is known about the entanglement of bipartite channels, called dynamical entanglement. Here we work with the partial transpose of a superchannel, and use it to define computable measures…

Quantum Physics · Physics 2020-11-02 Gilad Gour , Carlo Maria Scandolo

We study the degree to which quantum entanglement survives when a three-qubit entangled state is copied by using local and non-local processes, respectively, and investigate iterating quantum copying for the three-qubit system. There may…

Quantum Physics · Physics 2016-09-08 Zhao-Yang Tong , Le-Man Kuang

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

A general mathematical framework is presented to describe local equivalence classes of multipartite quantum states under the action of local unitary and local filtering operations. This yields multipartite generalizations of the singular…

Quantum Physics · Physics 2009-11-07 Frank Verstraete , Jeroen Dehaene , Bart De Moor

The quantum entanglement as one of very important resources has been widely used in quantum information processing. In this work, we present a new kind of genuine multipartite entanglement. It is derived from special geometric feature of…

Quantum Physics · Physics 2021-11-29 Ming-Xing Luo