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Related papers: Error exponents for entanglement concentration

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We present an efficient entanglement concentration protocol (ECP) for mobile electrons with charge detection. This protocol is quite different from other ECPs for one can obtain a maximally entangled pair from a pair of less-entangled state…

Quantum Physics · Physics 2015-06-04 Yu-Bo Sheng , Lan Zhou , Wei-Wen Cheng , Long-Yan Gong , Sheng-Mei Zhao

One of the main challenges of quantum information is the reliable verification of quantum entanglement. The conventional detection schemes require repeated measurement on a large number of identically prepared systems. This is hard to…

Quantum Physics · Physics 2018-03-07 Aleksandra Dimić , Borivoje Dakić

We present a practical entanglement distillation protocol (EDP) with linear optics for a genuine mixed state. Each components of the genuine mixed state is a pure less-entangled state. After successfully performing this EDP, we can obtain a…

Quantum Physics · Physics 2014-01-16 Yu-Bo Sheng , Lan Zhou , Xing-Fu Wang

The entanglement of an optically generated electron-hole pair in artificial quantum dot molecules is calculated considering the effects of decoherence by interaction with environment. Since the system evolves into a mixed states and due to…

Mesoscale and Nanoscale Physics · Physics 2016-08-24 H. S. Borges , L. Sanz , A. M. Alcalde

We propose a new approach to the problem of defining the degree of entanglement between two particles in a pure state with Hilbert spaces of arbitrary finite dimensions. The central idea is that entanglement gives rise to correlations…

Quantum Physics · Physics 2007-05-23 Markus A. Cirone

Entangled states are a crucial resource for quantum-based technologies such as quantum computers and quantum communication systems (1,2). Exploring new methods for entanglement generation is important for diversifying and eventually…

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

It is a specific type of quantum correlated state that achieves optimal precision in parameterestimation under unitary encoding. We consider the potential experimental limitation on probe entanglement, and find a relation between achievable…

Quantum Physics · Physics 2026-01-06 Debarupa Saha , Ujjwal Sen

Indefinite causal order is an evolving field with potential involvement in quantum technologies. Here we propose and study one possible scenario of practical application in quantum communication: a compound entanglement distillation…

Quantum Physics · Physics 2023-12-08 Zai Zuo , Michael Hanks , M. S. Kim

We propose schemes for entanglement concentration and purification for qubit systems encoded in flying atomic pairs. We use a cavity-quantum electrodynamics setting as the paradigmatic scenario within which our proposals can be implemented.…

Quantum Physics · Physics 2009-11-13 C. D. Ogden , M. Paternostro , M. S. Kim

In the performance analysis of quantum networks, it is common to approximate bipartite entangled states as either being Bell-diagonal or Werner states. We refer to these as twirled approximations because it is possible to bring any state to…

Quantum Physics · Physics 2025-09-23 Bethany Davies , Guus Avis , Stephanie Wehner

Bennett et al. proposed a family of protocols for entanglement distillation, namely, hashing, recurrence and breeding protocols. The last one is inferior to the hashing protocol in the asymptotic regime and has been investigated little. In…

Quantum Physics · Physics 2024-02-02 Ryutaroh Matsumoto

We consider asymptotic convertibility of an arbitrary sequence of bipartite pure states into another by local operations and classical communication (LOCC). We adopt an information-spectrum approach to address cases where each element of…

Quantum Physics · Physics 2018-03-14 Yong Jiao , Eyuri Wakakuwa , Tomohiro Ogawa

A connection between the state estimation problem and the separability problem is noticed and exploited to find efficient numerical algorithms to solve the first one. Based on these ideas, we also derive a systematic method to obtain upper…

Quantum Physics · Physics 2012-04-30 Miguel Navascues

Entanglement purification protocols, designed to improve the fidelity of Bell states over quantum networks for inter-node communications, have attracted significant attention over the last few decades. These protocols have great potential…

Quantum Physics · Physics 2024-05-07 Yue Shi , Chenxu Liu , Samuel Stein , Meng Wang , Muqing Zheng , Ang Li

We present a novel approach to spin-adapted coupled cluster theory. This approach is based on the entanglement of an open-shell molecule with electrons in a non-interacting bath; together they form a closed-shell state. For the total…

Chemical Physics · Physics 2023-05-22 Sarai Dery Folkestad , Bendik Støa Sannes , Henrik Koch

General formulas of entanglement concentration are derived by using an information-spectrum approach for the i.i.d. sequences and the general sequences of partially entangled pure states. That is, we derive general relations between the…

Quantum Physics · Physics 2016-11-17 Masahito Hayashi

The remarkable phenomenon of catalyst tells us that adding a catalyst could help state transformation. In this paper, we consider the problem of catalyst-assisted probabilistic coherence distillation for mixed states under strictly…

Quantum Physics · Physics 2020-01-13 C. L. Liu , D. L. Zhou

Squashed entanglement is a measure for the entanglement of bipartite quantum states. In this paper we present a lower bound for squashed entanglement in terms of a distance to the set of separable states. This implies that squashed…

Quantum Physics · Physics 2012-07-23 Fernando G. S. L. Brandao , Matthias Christandl , Jon Yard

We introduce an entanglement distillation (purification) protocol for supersinglet states composed of N qubits. The supersinglet state we target is a total spin zero state with zero spin variance, and has a fully entangled structure…

Quantum Physics · Physics 2025-09-26 Saeed Ahmad , Shuang Li , Jonathan Raghoonanan , Kaixuan Zhou , Valentin Ivannikov , Tim Byrnes