Spin squeezing and concurrence under Lee-Yang dephasing channels

TL;DR

This paper investigates how Lee-Yang dephasing channels affect spin squeezing and entanglement in probe spins, revealing conditions under which spin squeezing is enhanced and how entanglement relates to Lee-Yang zeros.

Contribution

It introduces a detailed analysis of spin squeezing and concurrence under Lee-Yang dephasing channels, highlighting their dependence on initial states and coupling configurations.

Findings

Spin squeezing performance can be improved depending on the coupling type.

Concurrence vanishing domains align with Lee-Yang zeros.

Entanglement properties are similar across different Lee-Yang dephasing channels.

Abstract

The Lee-Yang zeros are one-to-one mapping to zeros in the coherence of a probe spin coupled to a many-body system. Here, we study the spin squeezing under two different types of Lee-Yang dephasing channels in which the partition functions vanish at Lee-Yang zeros. Under the first type of the channels in which 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 channels in which 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 new experimental possibilities in many-body physics and extend a new perspective of the relationship between the entanglement and spin squeezing in probes-bath systems.