Witnessing entanglement between two atoms in dissipative cavities by the entropic uncertainty relation

2016 ◽  
Vol 94 (11) ◽  
pp. 1142-1147 ◽  
Author(s):  
Hong-Mei Zou ◽  
Mao-Fa Fang
Keyword(s):  
Quantum Information ◽  
Lower Bound ◽  
Uncertainty Relation ◽  
Quantum Information Processing ◽  
Equation Approach ◽  
Time Zone ◽  
Entanglement Witness ◽  
Entropic Uncertainty Relation ◽  
Cavity Coupling ◽  
Master Equation Approach

Based on the entropic uncertainty relation in the presence of quantum memory, the entanglement witness of two atoms in dissipative cavities is investigated by using the time-convolutionless master-equation approach. We discuss in detail the influences of the non-Markovian effect and the atom–cavity coupling on the lower bound of the entropic uncertainty relation and entanglement witness. The results show that, with the coupling increasing, the number of the time zone witnessed will increase so that the entanglement can be repeatedly witnessed. Enhancing the non-Markovian effect can add the number of the time zone witnessed and lengthen the time of entanglement witness. The results can be applied in quantum measurement, entanglement detecting, quantum cryptography task, and quantum information processing.

scholarly journals Tripartite entropic uncertainty relation under phase decoherence

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. A. Abdelghany ◽  
A.-B. A. Mohamed ◽  
M. Tammam ◽  
Watson Kuo ◽  
H. Eleuch
Keyword(s):  
Lower Bound ◽  
Uncertainty Relation ◽  
Nearest Neighbors ◽  
The Other ◽  
Uncertainty In Measurement ◽  
Entropic Uncertainty Relation ◽  
Specific Choice ◽  
Phase Decoherence ◽  
Time Invariant ◽  
Incompatible Observables

AbstractWe formulate the tripartite entropic uncertainty relation and predict its lower bound in a three-qubit Heisenberg XXZ spin chain when measuring an arbitrary pair of incompatible observables on one qubit while the other two are served as quantum memories. Our study reveals that the entanglement between the nearest neighbors plays an important role in reducing the uncertainty in measurement outcomes. In addition we have shown that the Dolatkhah’s lower bound (Phys Rev A 102(5):052227, 2020) is tighter than that of Ming (Phys Rev A 102(01):012206, 2020) and their dynamics under phase decoherence depends on the choice of the observable pair. In the absence of phase decoherence, Ming’s lower bound is time-invariant regardless the chosen observable pair, while Dolatkhah’s lower bound is perfectly identical with the tripartite uncertainty with a specific choice of pair.

Entanglement witness via quantum-memory-assisted entropic uncertainty relation

2017 ◽  
Vol 14 (12) ◽  
pp. 125208 ◽  
Author(s):  
Jiadong Shi ◽  
Zhiyong Ding ◽  
Tao Wu ◽  
Juan He ◽  
Lizhi Yu ◽  
...  
Keyword(s):  
Uncertainty Relation ◽  
Quantum Memory ◽  
Entanglement Witness ◽  
Entropic Uncertainty Relation

scholarly journals The quantum entropic uncertainty relation and entanglement witness in the two-atom system coupling with the non-Markovian environments

2014 ◽  
Vol 89 (11) ◽  
pp. 115101 ◽  
Author(s):  
Hong-Mei Zou ◽  
Mao-Fa Fang ◽  
Bai-Yuan Yang ◽  
You-Neng Guo ◽  
Wei He ◽  
...  
Keyword(s):  
Uncertainty Relation ◽  
Entanglement Witness ◽  
Entropic Uncertainty Relation ◽  
System Coupling ◽  
Atom System

scholarly journals Optimality of entropic uncertainty relations

2015 ◽  
Vol 13 (06) ◽  
pp. 1550045 ◽  
Author(s):  
Kais Abdelkhalek ◽  
René Schwonnek ◽  
Hans Maassen ◽  
Fabian Furrer ◽  
Jörg Duhme ◽  
...  
Keyword(s):  
Lower Bound ◽  
Numerical Investigation ◽  
Uncertainty Relation ◽  
Small Dimension ◽  
Uncertainty Relations ◽  
Complete Understanding ◽  
Entropic Uncertainty Relations ◽  
Entropic Uncertainty Relation ◽  
Analytical Results ◽  
Optimal Lower Bound

The entropic uncertainty relation proven by Maassen and Uffink for arbitrary pairs of two observables is known to be nonoptimal. Here, we call an uncertainty relation optimal, if the lower bound can be attained for any value of either of the corresponding uncertainties. In this work, we establish optimal uncertainty relations by characterizing the optimal lower bound in scenarios similar to the Maassen–Uffink type. We disprove a conjecture by Englert et al. and generalize various previous results. However, we are still far from a complete understanding and, based on numerical investigation and analytical results in small dimension, we present a number of conjectures.

scholarly journals Quantum Entanglement: Separability, Measure, Fidelity of Teleportation, and Distillation

2010 ◽  
Vol 2010 ◽  
pp. 1-57 ◽  
Author(s):  
Ming Li ◽  
Shao-Ming Fei ◽  
Xianqing Li-Jost
Keyword(s):  
Quantum Information ◽  
Quantum Entanglement ◽  
Information Science ◽  
Quantum Information Processing ◽  
Quantum Information Science ◽  
Entanglement Witness ◽  
Separability Criteria ◽  
Quantum Entangled States ◽  
Matrix Normal ◽  
Bloch Representation

Quantum entanglement plays crucial roles in quantum information processing. Quantum entangled states have become the key ingredient in the rapidly expanding field of quantum information science. Although the nonclassical nature of entanglement has been recognized for many years, considerable efforts have been taken to understand and characterize its properties recently. In this review, we introduce some recent results in the theory of quantum entanglement. In particular separability criteria based on the Bloch representation, covariance matrix, normal form and entanglement witness, lower bounds, subadditivity property of concurrence and tangle, fully entangled fraction related to the optimal fidelity of quantum teleportation, and entanglement distillation will be discussed in detail.

scholarly journals Entropic uncertainty relation under correlated dephasing channels

2018 ◽  
Vol 96 (7) ◽  
pp. 700-704 ◽  
Author(s):  
Göktuğ Karpat
Keyword(s):  
Quantum Mechanics ◽  
Standard Deviation ◽  
Lower Bound ◽  
Quantum System ◽  
Quantum Channel ◽  
Uncertainty Relation ◽  
Open Quantum System ◽  
Uncertainty Relations ◽  
Entropic Uncertainty Relation ◽  
Incompatible Observables

Uncertainty relations are a characteristic trait of quantum mechanics. Even though the traditional uncertainty relations are expressed in terms of the standard deviation of two observables, there exists another class of such relations based on entropic measures. Here we investigate the memory-assisted entropic uncertainty relation in an open quantum system scenario. We study the dynamics of the entropic uncertainty and its lower bound, related to two incompatible observables, when the system is affected by noise, which can be described by a correlated Pauli channel. In particular, we demonstrate how the entropic uncertainty for these two incompatible observables can be reduced as the correlations in the quantum channel grow stronger.

FOUR PHOTON POLARIZATION ENTANGLEMENT TESTS AND APPLICATIONS

2004 ◽  
Vol 02 (01) ◽  
pp. 133-147 ◽  
Author(s):  
M. BOURENNANE ◽  
M. EIBL ◽  
S. GAERTNER ◽  
C. KURTSIEFER ◽  
H. WEINFURTER ◽  
...  
Keyword(s):  
Quantum Information ◽  
Quantum Information Processing ◽  
Quantum Channels ◽  
Photon Polarization ◽  
Entanglement Witness ◽  
Photon State ◽  
Parametric Down Conversion ◽  
Local Polarization ◽  
Down Conversion ◽  
Decoherence Free Subspace

Multipartite entangled states are key elements for quantum information processing. Here we experimentally investigate the particular properties of a polarization-entangled four-photon state, which can be generated directly by second order parametric down-conversion. The perfect correlations and the invariance under local transformations enable one to encode one qubit of quantum information in a decoherence-free subspace and thus to communicate it safely over noisy quantum channels. Furthermore, we present an experimental method to detect genuine fourpartite entanglement using entanglement witness operators. The implementation of such operators requires only of few local polarization measurements but uniquely proves the genuine multipartite entanglement.

Steering entropic uncertainty of qutrit system

2020 ◽  
Vol 35 (16) ◽  
pp. 2050127
Author(s):  
Zhiming Huang ◽  
Dongwu Wu ◽  
Tianqing Wang ◽  
Yungang Bian ◽  
Wei Zhang
Keyword(s):  
Quantum Information ◽  
Quantum System ◽  
Uncertainty Relation ◽  
Quantum Memory ◽  
High Dimensional ◽  
Amplitude Damping ◽  
Entropic Uncertainty Relation ◽  
Information Tasks

High-dimensional quantum system plays an important role in quantum information tasks. However, the interaction between quantum system and environment would give rise to decoherence. In this paper, we examine the quantum-memory-assisted entropic uncertainty relation under amplitude damping (AD) decoherence. It is found that entropic uncertainty first inflates and then reduces to a nonzero value with the growing decoherence strength. In addition, it is revealed that the mixedness is not closely associated with entropic uncertainty which is different from the previous result. Furthermore, we construct a remarkably effective filtering operator to steer and reduce the entropic uncertainty. Our exploration might offer fresh insights into the dynamics and manipulation of the entropic uncertainty in high-dimensional quantum system.

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