2014/01/13 by Qiang Zheng, Yao Yao, Qiang, Zheng +3
Computer Science · Physics and Astronomy · #FOS: Physical sciences #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum Physics (quant-ph)
paper · pdf · doi:10.48550/arxiv.1401.2733
openalex publication_date 2014/01/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We investigate the parameter estimation problem in a two-qubit system, in which each qubit is independently interacting with its Markovian environment. We study in detail the sensitivity of the estimation on the decoherence rate γ and the two-qubit interaction strength v. In particular, the dynamics of quantum Fisher information are employed as a measure to quantify the precision of the estimations. We find that the quantum Fisher information with respect to the decoherence rate scales like t2/[exp(γt)-1] and exp(-2γt) in the unitary limit and the completely decoherent limit, respectively. When we estimate the interaction strength v, the quantum Fisher information shows oscillation behavior in term of time. In addition, our results provide further evidence that the entanglement of the input state may not enhance quantum metrology.