Correlation dynamics of three spin under a classical dephasing environment

TL;DR

This paper investigates how classical dephasing noise affects quantum correlations like entanglement and discord in a three-spin system, revealing that entanglement can be more resilient and that non-Markovian noise extends correlation lifetimes.

Contribution

It provides exact solutions for the dynamics of quantum correlations in a three-spin system under classical noise, including both Markovian and non-Markovian regimes, highlighting differences in robustness.

Findings

Entanglement can be more robust than quantum discord against classical dephasing.

Non-Markovian noise prolongs the survival time of quantum correlations.

Exact solutions for correlation dynamics under classical noise are derived.

Abstract

By starting from the stochastic Hamiltonian of the three correlated spins and modeling their frequency fluctuations as caused by dephasing noisy environments described by Ornstein-Uhlenbeck processes, we study the dynamics of quantum correlations, including entanglement and quantum discord. We prepared initially our open system with Greenberger-Horne-Zeilinger or W state and present the exact solutions for evolution dynamics of entanglement and quantum discord between three spins under both Markovian and non-Markovian regime of this classical noise. By comparison the dynamics of entanglement with that of quantum discord we find that entanglement can be more robust than quantum discord against this noise. It is shown that by considering non-Markovian extensions the survival time of correlations prolong.