Spin Squeezing And Concurrence Under Lee-Yang Dephasing Channels

The Lee-Yang zeros are one-to-one mapped to zeros in the coherence of a probe spin coupled to a many-body system. Here, we propose two different types of Lee-Yang dephasing channels, where the partition functions vanish at Lee-Yang zeros, and study the spin squeezing under them. Under the first type of channels where probes are coupled to their own bath, we find that the performance of spin squeezing is improved and its maximum only depends on the initial state. Moreover, the centers of all the concurrence vanishing domains are corresponding to the Lee-Yang zeros. Under the second type of the channel where probes are coupled to one bath together, the performance of spin squeezing is not improved, however, the concurrence shares almost the same properties under both channels. These results provide experimental possibilities in many-body physics and give an alternative perspective on the relationship between the entanglement and spin squeezing in probes-bath systems.