Quantum Fisher information and spin squeezing in one-axis twisting model

Abstract

We consider the quantum Fisher information and spin squeezing in one-axis twisting model with a coherent spin state $|\hat{I}{¸}_0,\ddot{I}{•}_0⟩$. We analytically discuss the dependence of the two parameters: spin squeezing parameter $\hat{I}{¾}_K^2$ and the average parameter estimation precision $\ddot{I}{‡}^2$ on the polar angle $\hat{I}{¸}_0$ and the azimuth angle $\ddot{I}{•}_0$. Moreover, we discuss the effects of the collisional dephasing on the dynamics of the two parameters. In this case, the analytical solution of $\hat{I}{¾}_K^2$ is also obtained.

14 pages, 4 figures