Fisher information of accelerated two-qubit system in the presence of the color and white noisy channels

2020 ◽  
Vol 34 (05) ◽  
pp. 2050027
Author(s):  
N. Metwally ◽  
F. Ebrahim
Keyword(s):  
Fisher Information ◽  
Quantum Fisher Information ◽  
Entangled State ◽  
Acceleration Process ◽  
Noise Strength ◽  
Initial State ◽  
Noisy Channels ◽  
Noise Effect ◽  
Single Qubit ◽  
Qubit System

In this paper, an accelerated two-qubit system initially prepared in maximum or partial entangled state, which interacts locally with white/color or white-color noises, is considered. Due to the acceleration process and the noise effect, the entanglement degraded. Therefore, the effect of noise strength, initial state settings and the acceleration on the survival entanglement are investigated by means of the concurrence. Moreover, the initial parameters that describe this system are estimated by using the quantum Fisher information, where two forms are considered, namely by using a single and two-qubit forms. It is shown that, by using the two-qubit form, the estimation degree of these parameters is larger than that displayed by using a single-qubit form.

scholarly journals Bidirectional teleportation using Fisher information

2020 ◽  
Vol 35 (33) ◽  
pp. 2050272
Author(s):  
C. Seida ◽  
A. El Allati ◽  
N. Metwally ◽  
Y. Hassouni
Keyword(s):  
Fisher Information ◽  
Uncertainty Principle ◽  
Quantum Fisher Information ◽  
Single Parameter ◽  
Numerical Calculations ◽  
Initial State ◽  
Better Than

In this contribution, we reformulated the bidirectional teleportation protocol suggested in Ref. 7, by means of Bloch vectors as well as the local operations are represented by using Pauli operators. Analytical and numerical calculations for the teleported state and Fisher information are introduced. It is shown that both quantities depend on the initial state settings of the teleported qubits and their triggers. The Fidelities and the Fisher information of the bidirectionally teleported states are maximized when the qubit and its trigger are polarized in the same direction. The minimum values are predicted if both initial qubits have different polarization or nonzero phase. The maximum values of the Fidelity and the quantum Fisher information are the same, but they are predicted at different polarization angles. We display that the multi-parameter form is much better than the single parameter form, where it satisfies the bounds of classical, entangled systems and the uncertainty principle.

Fisher and skew information for two-qubit Bell states under decoherence effects

2020 ◽  
Vol 18 (04) ◽  
pp. 2050018
Author(s):  
R. Laghmach ◽  
H. El Hadfi ◽  
B. Maroufi ◽  
M. Daoud
Keyword(s):  
Fisher Information ◽  
Dynamical Behavior ◽  
Quantum Fisher Information ◽  
Bell States ◽  
Thermal Entanglement ◽  
Noisy Channels ◽  
Phase Damping ◽  
Skew Information ◽  
Amplitude Damping Channel ◽  
Depolarizing Channel

We give the explicit expressions of quantum Fisher information and skew information for a two-qubit Bell states. We investigate their dynamics under the decoherence effects: phase-damping channel, depolarizing channel and amplitude-damping channel. We also discuss the thermal entanglement quantified by Wootters concurrence for these three decoherence channels and we compare its dynamical behavior with the quantum Fisher information and skew information. We then use this comparison to investigate the influence of noisy channels on thermal entanglement and its role in boosting the performance of metrology protocols. It is shown that the correlations in two-qubit Bell states are more resistant to phase-damping channel and depolarizing channels.

Freezing the driven pulsed information of a single qubit

2019 ◽  
Vol 97 (10) ◽  
pp. 1147-1153
Author(s):  
N. Metwally ◽  
F. Al-Shawaikh ◽  
S.S. Hassan
Keyword(s):  
Quantum Cryptography ◽  
Fisher Information ◽  
Secure Communication ◽  
Rectangular Pulse ◽  
Local Information ◽  
Final States ◽  
Initial State ◽  
Single Qubit

We use a rectangular pulse to freeze the possibility of estimating the coherent parameters (θ, [Formula: see text]) of a single qubit, the local information, and the fidelity of the driven qubit. The possibility of freezing these three quantities depends on the initial state settings and the strength of the pulse. It is shown that the freezing areas increase as the detuning increases, while they decrease at smaller values of the pulse strength. Moreover, as the Fisher information reaches its minimum bounds, the local information and the fidelity are maximized. We show that, when the Fisher information is completely frozen, the pulsed local information and the fidelity are frozen. The freezing degree depends on the initial detuning and the pulse strength. Our results show that, despite the initial and final states of the system being different, the amount of local information is independent of the initial state of the system. These results may be useful in the context of quantum cryptography, teleportation, and secure communication.

scholarly journals Quantum Fisher Information of W and GHZ State Superposition under Decoherence

2017 ◽  
Author(s):  
Volkan Erol
Keyword(s):  
Quantum System ◽  
Recent Work ◽  
Fisher Information ◽  
Quantum Fisher Information ◽  
Ghz State ◽  
Noisy Channels ◽  
Noise Parameters ◽  
Ghz States

We study the changes in quantum Fisher information (QFI) values for one quantum system consisting of a superposition of W and GHZ states. In a recent work [6], QFI values of this mentioned system studied. In this work, we extend this problem for the changes of QFI values in some noisy channels. We show the change in QFI depending on noise parameters. We report interesting results for different type of decoherence channels.

Coherence and quantum Fisher information in general single-qubit parameter estimation processes

2021 ◽  
Vol 104 (6) ◽  
Author(s):  
Jun-Long Zhao ◽  
Dong-Xu Chen ◽  
Yu Zhang ◽  
Yu-Liang Fang ◽  
Ming Yang ◽  
...  
Keyword(s):  
Parameter Estimation ◽  
Fisher Information ◽  
Quantum Fisher Information ◽  
Single Qubit
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