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Two pure orthogonal quantum states can be perfectly distinguished by sequential local action of multiple pairs of parties. However, this process typically leads to the complete dissolution of entanglement in the states being discriminated.…

Quantum Physics · Physics 2025-06-10 Debarupa Saha , Priya Ghosh , Kornikar Sen , Chirag Srivastava , Ujjwal Sen

We comment on the recent suggestion to use a family of local uncertainty relations as a standard way of quantifying entanglement in two-qubit systems. Some statements made on the applicability of the proposed "measures" are overly…

Quantum Physics · Physics 2016-08-16 Simon Samuelsson , Gunnar Björk

Quantum entanglement is a crucial resource for a wide variety of quantum technologies. However, the current state-of-art methods to generate quantum entanglement in optomechanical systems are not as efficient as all-optical methods…

We explore how entanglement of a general bipartite system evolves when one subsystem undergoes the action of an arbitrary noisy channel. It is found that the dynamics of entanglement for general bipartite systems under the influence of such…

Quantum Physics · Physics 2009-11-13 Zong-Guo Li , S. M. Fei , Z. D. Wang , W. M. Liu

We present a protocol to simulate the quantum correlations of an arbitrary bipartite state, when the parties perform a measurement according to two traceless binary observables. We show that $\log(d)$ bits of classical communication is…

Quantum Physics · Physics 2007-05-23 Julien Degorre , Sophie Laplante , Jérémie Roland

We introduce a measure Q of bipartite quantum correlations for arbitrary two-qubit states, expressed as a state-independent function of the density matrix elements. The amount of quantum correlations can be quantified experimentally by…

Quantum Physics · Physics 2012-04-16 Davide Girolami , Gerardo Adesso

A key problem in quantum information science is to determine optimal protocols for the interconversion of entangled states shared between remote parties. While for two parties a large number of results in this direction is available, the…

Quantum Physics · Physics 2025-05-26 Alexander Streltsov

We show that thresholds for fault-tolerant quantum computation are solely determined by the quality of single-system operations if one allows for d-dimensional systems with $8 \leq d \leq 32$. Each system serves to store one logical qubit…

Quantum Physics · Physics 2016-08-16 W. Dür , H. -J. Briegel

We study the monogamy and polygamy inequalities of unified entanglement in multipartite quantum systems. We first derive the monogamy inequality of unified-$(q, s)$ entanglement for multi-qubit states under arbitrary bipartition, and then…

Quantum Physics · Physics 2022-05-16 Mei-Ming Zhang , Naihuan Jing , Hui Zhao

We present a way of experimentally determining the concurrence in terms of the expectation values of local observables for arbitrary multipartite pure states. In stead of the joint measurements on two copies of a state in the experiment for…

Quantum Physics · Physics 2015-05-14 Shao-Ming Fei , Ming-Jing Zhao , Kai Chen , Zhi-Xi Wang

Quantifying entanglement is a work in progress which is important for the active field of quantum information and computation. A measure of bipartite pure state entanglement is proposed here, named entanglement coherence, which is…

Quantum Physics · Physics 2022-02-15 Neha Pathania , Tabish Qureshi

Detecting entanglement in multipartite quantum states is an inherently probabilistic process, typically with a few measured samples. The level of confidence in entanglement detection quantifies the scheme's validity via the probability that…

The problem of optimally estimating an unknown unitary quantum operation with the aid of entanglement is addressed. The idea is to prepare an entangled pair, apply the unknown unitary to one of the two parts and then measure the joint…

Quantum Physics · Physics 2007-05-23 Manuel A. Ballester

We propose the usage of persistent homologies to characterize multipartite entanglement. On a multi-qubit data set we introduce metric-like measures defined only in terms of bipartite entanglement and then we derive barcodes. We show that…

Quantum Physics · Physics 2018-09-26 Alessandra Di Pierro , Stefano Mancini , Laleh Memarzadeh , Riccardo Mengoni

We revisit the problem of detection of entanglement of an unknown two-qubit state using minimal resources. Using weak values and just two copies of an arbitrary two-qubit state, we present a protocol where a post selection measurement in…

Quantum Physics · Physics 2019-01-17 Suchetana Goswami , Sagnik Chakraborty , Sibasish Ghosh , A. S. Majumdar

The ability to reach a maximally entangled state from a separable one through the use of a two-qubit unitary operator is analyzed for mixed states. This extension from the known case of pure states shows that there are at least two families…

Quantum Physics · Physics 2018-04-06 Zhe Guan , Huan He , Yong-Jian Han , Chuan-Feng Li , Fernando Galve , Guang-Can Guo

The properties of some complex many body systems can be modeled by introducing in the dissipative dynamics of each single component a set of kinetic constraints that depend on the state of the neighbor systems. Here, we characterize this…

Quantum Physics · Physics 2015-06-17 Adrian A. Budini

Entanglement is a striking feature of quantum mechanics, and it has a key property called unextendibility. In this paper, we present a framework for quantifying and investigating the unextendibility of general bipartite quantum states.…

Quantum Physics · Physics 2024-03-28 Kun Wang , Xin Wang , Mark M. Wilde

Entanglement is one of the key resources required for quantum computation, so experimentally creating and measuring entangled states is of crucial importance in the various physical implementations of a quantum computer. In superconducting…

A generic scheme for the parametrization of mixed state systems is introduced, which is then adapted to bipartite systems, especially to a 2-qubit system. Various features of 2-qubit entanglement are analyzed based on the scheme. Our…

Quantum Physics · Physics 2022-07-15 Otto C. W. Kong , Hock King Ting