On measures of quantum entanglement — A brief review

2016 ◽  
Vol 14 (06) ◽  
pp. 1640024 ◽  
Author(s):  
Debasis Sarkar
Keyword(s):  
Quantum Mechanics ◽  
Information Processing ◽  
Quantum Information ◽  
Quantum Entanglement ◽  
Quantum Correlation ◽  
Composite System ◽  
Quantum Information Processing ◽  
Bipartite Entanglement

Entanglement is one of the most useful resources in quantum information processing. It is effectively the quantum correlation between different subsystems of a composite system. Mathematically, one of the most hard tasks in quantum mechanics is to quantify entanglement. However, progress in this field is remarkable but not complete yet. There are many things to do with quantification of entanglement. In this review, we will discuss some of the important measures of bipartite entanglement.

scholarly journals Entanglement enhanced distinguishability of coherence-breaking channels

2019 ◽  
Vol 17 (04) ◽  
pp. 1950036
Author(s):  
Long-Mei Yang ◽  
Tao Li ◽  
Shao-Ming Fei ◽  
Zhi-Xi Wang
Keyword(s):  
Quantum Mechanics ◽  
Information Processing ◽  
Quantum Information ◽  
Quantum Entanglement ◽  
Error Probability ◽  
Quantum Information Processing ◽  
Superposition Principle ◽  
Important Resource ◽  
Minimal Error ◽  
Different Types

Originating from the superposition principle in quantum mechanics, coherence has been extensively studied as a kind of important resource in quantum information processing. We investigate the distinguishability of coherence-breaking channels with the help of quantum entanglement. By explicitly computing the minimal error probability of channel discrimination, it is shown that entanglement can enhance the capacity of coherence-breaking channel distinguishability with same types for some cases while it cannot be enhanced for some other cases. For coherence-breaking channels with different types, the channel distinguishability cannot be enhanced via entanglement.

QUANTUM COMPLEXITY THEORY GOALS AND CHALLENGES

2005 ◽  
Vol 03 (01) ◽  
pp. 31-39 ◽  
Author(s):  
JOZEF GRUSKA
Keyword(s):  
Quantum Mechanics ◽  
Information Processing ◽  
Quantum Information ◽  
Complexity Theory ◽  
Quantum Information Processing ◽  
Short Review ◽  
Quantum Complexity ◽  
Quantum Complexity Theory

Quantum complexity theory is a powerful tool that provides deep insights into Quantum Information Processing (QIP) and aims to do that also for Quantum Mechanics (QM), in general. This paper is a short review of the main and new motivations, goals, tools, results and challenges of quantum complexity, oriented mainly for pedestrians.

Quantum-entanglement storage and extraction in quantum network node

2018 ◽  
Vol 16 (01) ◽  
pp. 1850009 ◽  
Author(s):  
ZhuoYu Shan ◽  
Yong Zhang
Keyword(s):  
Information Processing ◽  
Quantum Information ◽  
Quantum Entanglement ◽  
Information Technologies ◽  
Quantum Information Processing ◽  
Bell State ◽  
Nitrogen Vacancy ◽  
Quantum Network ◽  
Nuclear Spins ◽  
Nv Centers

Quantum computing and quantum communication have become the most popular research topic. Nitrogen-vacancy (NV) centers in diamond have been shown the great advantage of implementing quantum information processing. The generation of entanglement between NV centers represents a fundamental prerequisite for all quantum information technologies. In this paper, we propose a scheme to realize the high-fidelity storage and extraction of quantum entanglement information based on the NV centers at room temperature. We store the entangled information of a pair of entangled photons in the Bell state into the nuclear spins of two NV centers, which can make these two NV centers entangled. And then we illuminate how to extract the entangled information from NV centers to prepare on-demand entangled states for optical quantum information processing. The strategy of engineering entanglement demonstrated here maybe pave the way towards a NV center-based quantum network.

scholarly journals Environmental Effects on Nonlocal Correlations

Quanta ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 57-67
Author(s):  
Tamal Guha ◽  
Bihalan Bhattacharya ◽  
Debarshi Das ◽  
Some Sankar Bhattacharya ◽  
Amit Mukherjee ◽  
...  
Keyword(s):  
Quantum Mechanics ◽  
Information Processing ◽  
Quantum Information ◽  
Quantum Information Processing ◽  
Classical Mechanics ◽  
Complete Loss ◽  
Quantum Channels ◽  
Output State ◽  
Environmental Interactions ◽  
Nonlocal Correlations

Environmental interactions are ubiquitous in practical instances of any quantum information processing protocol. The interaction results in depletion of various quantum resources and even complete loss in numerous situations. Nonlocality, which is one particular quantum resource marking a significant departure of quantum mechanics from classical mechanics, meets the same fate. In the present work we study the decay in nonlocality to the extent of the output state admitting a local hidden state model. Using some fundamental quantum channels we also demonstrate the complete decay in the resources in the purview of the Bell–Clauser–Horne–Shimony–Holt inequality and a three-settings steering inequality. We also obtain bounds on the parameter of the depolarizing map for which it becomes steerability breaking pertaining to a general class of two qubit states.Quanta 2019; 8: 57–67.

Quantum contextuality of YO-13 rays

2021 ◽  
Vol 36 (12) ◽  
pp. 2150088
Author(s):  
Jie Zhou ◽  
Hui-Xian Meng ◽  
Wei-Min Shang ◽  
Jing-Ling Chen
Keyword(s):  
Quantum Computing ◽  
Information Processing ◽  
Quantum Information ◽  
Quantum Correlation ◽  
Quantum Physics ◽  
Quantum Information Processing ◽  
Experimental Tests ◽  
Dimensional System ◽  
Quantum Contextuality ◽  
Fundamental Quantum Physics

Quantum contextuality, a more general quantum correlation, is an important resource for quantum computing and quantum information processing. Meanwhile, quantum contextuality plays an important role in fundamental quantum physics. Yu and Oh (YO) proposed a proof of the Kochen–Specker theorem for a qutrit with only 13 rays. Here, we further study quantum contextuality of YO-13 rays using the inequality approach. The maximum quantum violation value of the optimal noncontextuality inequality constructed by YO-13 rays is increased to 11.9776 in the four-dimensional system, which is larger than 11.6667 in the qutrit system. The result shows that the set of YO-13 rays has stronger quantum contextuality in the four-dimensional system. Moreover, we provide an all-versus-nothing proof (i.e. Hardy-like proof) to study YO-13 rays without using any inequality, which is easily applied to experimental tests. Our results will further deepen the understanding of YO-13 rays.

scholarly journals ENTANGLEMENT OF IDENTICAL PARTICLES AND REFERENCE PHASE UNCERTAINTY

2003 ◽  
Vol 01 (04) ◽  
pp. 427-441 ◽  
Author(s):  
JOHN A. VACCARO ◽  
FABIO ANSELMI ◽  
HOWARD M. WISEMAN
Keyword(s):  
Information Processing ◽  
Quantum Information ◽  
Quantum Information Processing ◽  
Invariant Subspaces ◽  
Bipartite Entanglement ◽  
Identical Particles ◽  
Phase Uncertainty ◽  
Reference Phase

We have recently introduced a measure of the bipartite entanglement of identical particles, E P , based on the principle that entanglement should be accessible for use as a resource in quantum information processing. We show here that particle entanglement is limited by the lack of a reference phase shared by the two parties, and that the entanglement is constrained to reference-phase invariant subspaces. The super-additivity of E P results from the fact that this constraint is weaker for combined systems. A shared reference phase can only be established by transferring particles between the parties, that is, with additional nonlocal resources. We show how this nonlocal operation can increase the particle entanglement.

Measurement-induced nonlocality in the two-qubit Heisenberg XY model

2015 ◽  
Vol 29 (15) ◽  
pp. 1550098 ◽  
Author(s):  
Wen-Xue Chen ◽  
Yu-Xia Xie ◽  
Xiao-Qiang Xi
Keyword(s):  
Magnetic Field ◽  
Information Processing ◽  
Quantum Information ◽  
External Magnetic Field ◽  
Potential Application ◽  
Quantum Correlation ◽  
Quantum Information Processing ◽  
Quantum Correlations ◽  
Xy Model ◽  
Anisotropic Parameter

Quantum correlations are essential for quantum information processing (QIP). Measurement-induced nonlocality (MIN) is a good measure of quantum correlation, and is favored for its conceptual implication and potential application. We investigated here the particular behaviors of the geometric and entropic measures of MIN in the two-qubit Heisenberg XY model and revealed the effects of anisotropic parameter γ and the external magnetic field B on them. Our results showed that both γ and B can serve as efficient controlling parameters for tuning MIN in the XY model.

scholarly journals Quantum Mechanics and the Origin of Life

2004 ◽  
Vol 213 ◽  
pp. 237-244
Author(s):  
Paul Davies
Keyword(s):  
Quantum Mechanics ◽  
Information Processing ◽  
Quantum Information ◽  
Quantum Computation ◽  
Origin Of Life ◽  
Quantum Information Processing ◽  
Quantum Computer ◽  
The Origin Of Life ◽  
Concept Of Information

The race to build a quantum computer has led to a radical re-evaluation of the concept of information. In this paper I conjecture that life, defined as an information processing and replicating system, may be exploiting the considerable efficiency advantages offered by quantum computation, and that quantum information processing may dramatically shorten the odds for life originating from a random chemical soup. The plausibility of this conjecture rests, however, on life somehow circumventing the decoherence effects of the environment. I offer some speculations on ways in which this might happen.

scholarly journals THE PHYSICS OF QUANTUM INFORMATION: COMPLEMENTARITY, UNCERTAINTY, AND ENTANGLEMENT

2013 ◽  
Vol 11 (08) ◽  
pp. 1330002 ◽  
Author(s):  
JOSEPH M. RENES
Keyword(s):  
Information Theory ◽  
Quantum Mechanics ◽  
Information Processing ◽  
Quantum Information ◽  
Quantum Information Processing ◽  
Quantum Information Theory ◽  
Wave Particle Duality ◽  
Double Slit Experiment ◽  
Slit Experiment ◽  
Double Slit

Complementarity is one of the central mysteries of quantum mechanics, dramatically illustrated by the wave-particle duality in Young's double-slit experiment, and famously regarded by Feynman as "impossible, absolutely impossible to describe classically, [and] which has in it the heart of quantum mechanics" (emphasis original).1 The overarching goal of this thesis is to demonstrate that complementarity is also at the heart of quantum information theory, that it allows us to make (some) sense of just what information "quantum information" refers to, and that it is useful in understanding and constructing quantum information processing protocols.

scholarly journals CAN QUANTUM MECHANICS HELP DISTRIBUTED COMPUTING?

2010 ◽  
Vol 08 (01n02) ◽  
pp. 259-269
Author(s):  
ANNE BROADBENT ◽  
ALAIN TAPP
Keyword(s):  
Quantum Mechanics ◽  
Information Processing ◽  
Quantum Information ◽  
Distributed Computing ◽  
Communication Complexity ◽  
Quantum Information Processing ◽  
Distributed Computation ◽  
Distributed Tasks

We present a brief survey of results where quantum information processing is useful for performing distributed computation tasks. We describe problems that are impossible to solve using classical resources but that become feasible with the help of quantum mechanics. We also give examples where the use of quantum information significantly reduces the need for communication. The main focus of the survey is on communication complexity but we also address other distributed tasks.

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