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Open Systems & Information Dynamics

Non-Markovian Dynamics of Spin Squeezing Under Detuning Modulation

Xing Mao Xiao, Jiaju Wu, Wo-Jun Zhong, Yan‐Ling Li

Published Mar 1, 2017• 1 citation
Publisher

Abstract

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.

DOI
10.1142/s1230161217500032

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We study the decoherence of spin squeezing under non-Markovian channels and consider an ensemble of NNN independent spin-1/21/21/2 particles with exchange symmetry. Each spin interacts with its own bath, and the baths are independent and identical. For this kind of open system, the spin squeezing under decoherence can be investigated from the dynamics of the local expectations. The reduced dynamics is obtained by the exact hierarchy equation method. The numerical results show that the spin squeezing may display both sudden and asymptotic vanishing; however, the revival phenomenon does not happen. In contrast, the concurrence shows multiple sudden vanishing and revival phenomena.
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