We study the von Neumann entropy of the partial trace of a system of 2 two-level atoms (qubits) in a dispersive cavity where the atoms are interacting collectively with a single-mode electromagnetic field in the cavity. We make a contrast of this entanglement entropy with the spin squeezing property of the system. We find a close relationship between this von Neumann entropy and the spin squeezing of the system. We observe that this entanglement entropy attains its maximum value when the spin squeezing in the system goes to its maximum and is zero when the spin squeezing in the system vanishes.

中文翻译：

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色散腔中的冯诺依曼熵

我们研究了色散腔中 2 个两级原子（量子位）系统的部分迹的冯诺依曼熵，其中原子与腔中的单模电磁场共同相互作用。我们将这种纠缠熵与系统的自旋压缩特性进行了对比。我们发现这个冯诺依曼熵与系统的自旋压缩之间有着密切的关系。我们观察到，当系统中的自旋挤压达到最大值时，该纠缠熵达到最大值，当系统中的自旋挤压消失时，该熵为零。