Robust stationary distributed discord in Jordan-Wigner fermion system under perturbations of initial state

TL;DR

This paper studies the robustness of stationary quantum discord in Jordan-Wigner fermion systems under initial state perturbations, showing that stationarity persists despite parasitic polarizations but may alter discord distribution.

Contribution

It demonstrates that quantum discord stationarity in Jordan-Wigner fermion clusters withstands certain initial state perturbations, analyzing how parasitic polarizations deform discord distribution.

Findings

Stationarity of quantum discord is robust against certain initial state perturbations.

Parasitic polarizations can deform the distribution of pairwise discord.

Clusters of correlated fermions may be destroyed by polarization-induced deformations.

Abstract

We investigate the Jordan-Wigner fermion clusters with the stationary distributed pairwise quantum discord. Such clusters appear after the Jordan-Wigner transformation of a spin chain governed by the nearest-neighbor XY-Hamiltonian with the particular initial state having one polarized node. We show that the quantum discord stationarity in such systems is not destroyed by the "parasitic" polarization of at least two types. First type appears because the initial state with a single polarized node is hardly realizable experimentally, so that the low polarization of neighboring nodes must be taken into account. Second, the additional noise-polarization of all nodes is unavoidable. Although the stationarity may not be destroyed by perturbations of the above two types, the parasitic polarizations deform the distribution of the pairwise discord and may destroy the clusters of correlated fermions with equal pairwise discords. Such deformations are studied in this paper.