Time-Invariant Discord in Dynamically Decoupled Systems

TL;DR

This paper investigates how dynamical decoupling pulses can preserve quantum and classical correlations, specifically time-invariant discord, in two qubits undergoing local dephasing, revealing conditions for creating invariant discord.

Contribution

It provides new insights into the creation and preservation of time-invariant discord using dynamical decoupling in dephasing systems.

Findings

Dynamical decoupling can preserve quantum and classical correlations.

Necessary conditions for creating time-invariant discord are identified.

The study links information flow dynamics with correlation preservation.

Abstract

Dynamical decoupling protocols are one of the most used tools for efficient quantum error corrections and for reservoir engineering. In this paper we study the effect of dynamical decoupling pulses on the preservation of both quantum and classical correlations, and their influence on the intriguing phenomenon of time-invariant discord. We study two qubits experiencing local dephasing with an Ohmic class spectrum and subject to dynamical decoupling protocols. We investigate the connection between the dynamics of both classical and quantum correlations and the behaviour of information flow between system and environment. Finally, we establish a set of necessary conditions for which time-invariant discord can be created using dynamically decoupling techniques.