Abstract Recently, the phase parametric estimation for a single qubit system driven by a phase noisy laser under non-Markovian dynamics has been reported. We here generalize the single-parameter estimation to the two-parameter scenario where a two-qubit system is influenced by correlated phase noisy laser, and compare the performances of two-parameter estimation in both individual and simultaneous strategies by using the quantum Fisher information and the quantum Fisher information matrix, respectively.Our results show the phase parametric estimation precision can be improved due to the memory effect arising from successive applications of the noisy laser. With the memory coefficient $\mu$ increasing, the precision of parameter estimation becomes more accuracy. Besides, the phase parameter estimation precision can be well enhanced by engineering the ratios of classical phase noisy laser rate and system-environment coupling strength dependent of Markovian or non-Markovian regions. What's more, we find the simultaneous estimation of two-phase parameters is not always advantageous over the individual strategy.Abstract Recently, the phase parametric estimation for a single qubit system driven by a phase noisy laser under non-Markovian dynamics has been reported. We here generalize the single-parameter estimation to the two-parameter scenario where a two-qubit system is influenced by correlated phase noisy laser, and compare the performances of two-parameter estimation in both individual and simultaneous strategies by using the quantum Fisher information and the quantum Fisher information matrix, respectively.Our results show the phase parametric estimation precision can be improved due to the memory effect arising from successive applications of the noisy laser. With the memory coefficient $\mu$ increasing, the precision of parameter estimation becomes more accuracy. Besides, the phase parameter estimation precision can be well enhanced by engineering the ratios of classical phase noisy laser rate and system-environment coupling strength dependent of Markovian or non-Markovian regions. What's more, we find the simultaneous estimation of two-phase parameters is not always advantageous over the individual strategy.

Physica ScriptaSep 22, 20231 citation

Squeezing of a two-level system due to classical phase noisy laser

You-neng Guo, Wei Li, Hu Dong

Abstract Based on the Heisenberg uncertainty relation and the entropy uncertainty relation, the nonclassical effects described by variance squeezing and entropy squeezing for a two-level system driven by a classical phase noisy laser are investigated. Analytical expressions of the variance squeezing and entropy squeezing subjected to the classical phase noisy laser are derived. Our results show that the nonclassical squeezed effects can be protected for a long time in both the Markovian and non-Markovian regions by controlling the ratios between the phase diffusion rate and the system-laser coupling strength. Besides, we also develop an effective strategy to enhance the nonclassical squeezed effects with the help of filtering operation. The underlying physical mechanism to enhance the squeezing is also analyzed.Abstract Based on the Heisenberg uncertainty relation and the entropy uncertainty relation, the nonclassical effects described by variance squeezing and entropy squeezing for a two-level system driven by a classical phase noisy laser are investigated. Analytical expressions of the variance squeezing and entropy squeezing subjected to the classical phase noisy laser are derived. Our results show that the nonclassical squeezed effects can be protected for a long time in both the Markovian and non-Markovian regions by controlling the ratios between the phase diffusion rate and the system-laser coupling strength. Besides, we also develop an effective strategy to enhance the nonclassical squeezed effects with the help of filtering operation. The underlying physical mechanism to enhance the squeezing is also analyzed.

Laser Physics LettersAug 13, 20202 citations

Coherent dynamics of a qubit–oscillator system in a noisy environment

Wei Wu, Jun-Qing Cheng

arXiv:1712.09486Quantum Information ProcessingSep 26, 201810 citations

Coherence, correlation and non-Markovianity in qubit systems

Ning Tang, Wen Cheng, Hao‐Sheng Zeng

The European Physical Journal DSep 30, 20147 citations

\mu

increasing, the precision of parameter estimation becomes more accuracy. Besides, the phase parameter estimation precision can be well enhanced by engineering the ratios of classical phase noisy laser rate and system-environment coupling strength dependent of Markovian or non-Markovian regions. What's more, we find the simultaneous estimation of two-phase parameters is not always advantageous over the individual strategy.