The dynamics of spin squeezing of an ensemble of N separate spin-1/2 particles, each coupled to a zero-temperature non-Markovian reservoir have been investigated. We show that the initial spin squeezing could be prolonged for a long time by utilizing detuning modification. We further explore that the spin squeezing sudden death (SSSD) could be circumvented with the increasing of detuning. By comparison with the results in Markovian regime with detuning and those in non-Markovian regime without detuning, we conclude that the disappearance of SSSD and the robust preservation of spin squeezing should be attributed to the combination of detuning and non-Markovian effect. The present results may be of direct importance for quantum metrology in open systems.
Spin squeezing, entanglement and quantum metrology with Bose–Einstein condensates
