Quantum Fisher information for a single qubit system

2012 ◽  
Vol 66 (3) ◽  
Author(s):  
S. Abdel-Khalek ◽  
K. Berrada ◽  
A. S. F. Obada
Keyword(s):  
Fisher Information ◽  
Quantum Fisher Information ◽  
Single Qubit ◽  
Qubit System

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.

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

Quantum Fisher Information of a Two-Qubit System in Non-Markovian Environment

2019 ◽  
Vol 59 (1) ◽  
pp. 149-158
Author(s):  
Yao-Hua Hu ◽  
Yong-Gang Tan ◽  
Hai-Feng Yang ◽  
Lei-Ming Cao
Keyword(s):  
Fisher Information ◽  
Quantum Fisher Information ◽  
Markovian Environment ◽  
Qubit System

scholarly journals Effects of partial measurements on quantum resources and quantum Fisher information of a teleported state in a relativistic scenario

2020 ◽  
Vol 476 (2239) ◽  
pp. 20200378
Author(s):  
M. Jafarzadeh ◽  
H. Rangani Jahromi ◽  
M. Amniat-Talab
Keyword(s):  
Fisher Information ◽  
Quantum Coherence ◽  
Quantum Fisher Information ◽  
Optimal Estimation ◽  
Dirac Field ◽  
Unruh Effect ◽  
Single Qubit ◽  
Maximum Value ◽  
Phase Parameter ◽  
The One

We address the teleportation of single- and two-qubit quantum states, parametrized by weight θ and phase ϕ parameters, in the presence of the Unruh effect experienced by a mode of a free Dirac field. We investigate the effects of the partial measurement (PM) and partial measurement reversal (PMR) on the quantum resources and quantum Fisher information (QFI) of the teleported states. In particular, we discuss the optimal behaviour of the QFI, quantum coherence (QC) as well as fidelity with respect to the PM and PMR strength and examine the effect of the Unruh noise on optimal estimation. It is found that, in the single-qubit scenario, the PM (PMR) strength at which the optimal estimation of the phase parameter occurs is the same as the PM (PMR) strength with which the teleportation fidelity and the QC of the teleported single-qubit state reaches its maximum value. On the other hand, generalizing the results to two-qubit teleportation, we find that the encoded information in the weight parameter is better protected against the Unruh noise in two-qubit teleportation than in the one-qubit scenario. However, extraction of information encoded in the phase parameter is more efficient in single-qubit teleportation than in the two-qubit version.

Quantum Fisher information for a qubit system placed inside a dissipative cavity

2012 ◽  
Vol 376 (17) ◽  
pp. 1412-1416 ◽  
Author(s):  
K. Berrada ◽  
S. Abdel-Khalek ◽  
A.-S.F. Obada
Keyword(s):  
Fisher Information ◽  
Quantum Fisher Information ◽  
Qubit System
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