Optimal quantum channel estimation of two interacting qubits subject to decoherence

We investigate the estimation of the quantum channel parameter for a two-qubit system with each qubit independently interacting with its Markovian environment. The dynamics of quantum Fisher information in this system is studied and employed as a measure to quantify the precision of the estimation....

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Bibliographic Details
Published in:The European physical journal. D, Atomic, molecular, and optical physics Vol. 68; no. 6
Main Authors: Zheng, Qiang, Yao, Yao, Li, Yong
Format: Journal Article
Language:English
Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.06.2014
EDP Sciences
Subjects:
Applications of Nonlinear Dynamics and Chaos Theory
Atomic
Classical and quantum physics: mechanics and fields
Exact sciences and technology
Foundations, theory of measurement, miscellaneous theories (including aharonov-bohm effect, bell inequalities, berry's phase)
Molecular
Optical and Plasma Physics
Physical Chemistry
Physics
Physics and Astronomy
Quantum information
Quantum Information Technology
Quantum mechanics
Quantum Physics
Regular Article
Spectroscopy/Spectrometry
Spintronics
Quantum Information
Quantum decoherence
Quantum information
Quantum entanglement
Quantum bit
Fisher information
ISSN:1434-6060, 1434-6079
Online Access:Get full text
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Summary:We investigate the estimation of the quantum channel parameter for a two-qubit system with each qubit independently interacting with its Markovian environment. The dynamics of quantum Fisher information in this system is studied and employed as a measure to quantify the precision of the estimation. We find that the dynamic behavior of quantum Fisher information with respect to the decoherence rate γ is proportional to t 2 /[exp( γt ) − 1] and exp(−2 γt ) in the unitary limit and the completely decoherent limit, respectively. We also study the evolution of quantum Fisher information with respect to the interaction strength, which shows oscillating behavior. Furthermore, we show that the increase in entanglement of the input state may not enhance the precision of quantum estimation.
ISSN:1434-6060
1434-6079
DOI:10.1140/epjd/e2014-50047-1