Achieving spin-squeezed states by quench dynamics in a quantum chain
Abstract
We study the time evolution of spin squeezing in the one-dimensional spin-1/2 XY model subject to a sudden quantum quench of a transverse magnetic field. The initial state is selected from the ground state phase diagram of the model, consisting of ferro- and paramagnetic phases separated by a critical value of the transverse field. Our analysis, based on exact results for the model, reveals that by a proper choice of protocol, a quantum quench from an unsqueezed state can create spin squeezed nonequilibrium states. We also identify a nonanalyticity in the long-time average of the spin-squeezing parameter when quenching to the equilibrium quantum critical point. This suggests that the ferro- and paramagnetic phases also define distinct phases for how the transverse field redistributes quantum fluctuations among the spin components away from equilibrium.
Cite
@article{arxiv.2108.13805,
title = {Achieving spin-squeezed states by quench dynamics in a quantum chain},
author = {Hadi Cheraghi and Saeed Mahdavifar and Henrik Johannesson},
journal= {arXiv preprint arXiv:2108.13805},
year = {2022}
}
Comments
14 pages, 10 figures, Revised version, Added references, corrected calculation of off-diagonal spin correlations