A novel scheme is proposed to estimate three environmental parameters,the detuning,the temperature and the squeezing strength with one-qubit or two-qubit probes.Quantum Fisher information and the fidelity of the atom ...A novel scheme is proposed to estimate three environmental parameters,the detuning,the temperature and the squeezing strength with one-qubit or two-qubit probes.Quantum Fisher information and the fidelity of the atom probes are calculated.When the detuning between the frequency of cavity field and the atomic transition frequency is estimated,the dynamics of quantum Fisher information shows oscillatory and rising behaviors.To estimate the temperature of the thermal reservoir,the one-qubit probe with the superposition initial state is more favorable than the two-qubit probe with the entangled initial state.When the squeezing strength of the squeezed vacuum reservoir is estimated,we find that the estimation precision is significantly improved by utilizing the two-qubit probe with the maximal entangled initial state.Our work provides a potential application in the open quantum system and quantum information processing.展开更多
Simultaneously optimizing the estimation of the centroid and separation of two incoherent optical point sources is constrained by a tradeoff relation determined by an incompatibility coefficient.At the Rayleigh distan...Simultaneously optimizing the estimation of the centroid and separation of two incoherent optical point sources is constrained by a tradeoff relation determined by an incompatibility coefficient.At the Rayleigh distance,the incompatibility coefficient vanishes and thus the tradeoff relation no longer restricts the simultaneous optimization of measurement for a joint estimation.We construct such a joint optimal measurement by an elaborated analysis on the operator algebra of the symmetric logarithmic derivative.Our work not only confirms the existence of a joint optimal measurement for this specific imaging model,but also gives a promising method to characterize the condition on measurement compatibility for general multiparameter estimation problems.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.91536115 and 11534008)Natural Science Foundation of Shaanxi Province,China(Grant No.2016JM1005)。
文摘A novel scheme is proposed to estimate three environmental parameters,the detuning,the temperature and the squeezing strength with one-qubit or two-qubit probes.Quantum Fisher information and the fidelity of the atom probes are calculated.When the detuning between the frequency of cavity field and the atomic transition frequency is estimated,the dynamics of quantum Fisher information shows oscillatory and rising behaviors.To estimate the temperature of the thermal reservoir,the one-qubit probe with the superposition initial state is more favorable than the two-qubit probe with the entangled initial state.When the squeezing strength of the squeezed vacuum reservoir is estimated,we find that the estimation precision is significantly improved by utilizing the two-qubit probe with the maximal entangled initial state.Our work provides a potential application in the open quantum system and quantum information processing.
基金supported by the National Natural Science Foundation of China (Grants No.12275062,No.11935012,and No.61871162)。
文摘Simultaneously optimizing the estimation of the centroid and separation of two incoherent optical point sources is constrained by a tradeoff relation determined by an incompatibility coefficient.At the Rayleigh distance,the incompatibility coefficient vanishes and thus the tradeoff relation no longer restricts the simultaneous optimization of measurement for a joint estimation.We construct such a joint optimal measurement by an elaborated analysis on the operator algebra of the symmetric logarithmic derivative.Our work not only confirms the existence of a joint optimal measurement for this specific imaging model,but also gives a promising method to characterize the condition on measurement compatibility for general multiparameter estimation problems.
