Shielding quantum discord through continuous dynamical decoupling

TL;DR

This paper explores how continuous dynamical decoupling can protect quantum discord in a two-qubit system from environmental errors, analyzing the effects of temperature and initial states on the shielding effectiveness.

Contribution

It demonstrates the effectiveness and limitations of continuous dynamical decoupling in preserving quantum discord under different environmental conditions.

Findings

Quantum discord can be temporarily preserved using continuous dynamical decoupling.

The effectiveness of shielding decreases with increasing temperature.

The preservation time depends on the initial state and environmental parameters.

Abstract

This work investigates the use of dynamical decoupling to shield quantum discord from errors introduced by the environment. Specifically, a two-qubits system interacting with independent baths of bosons is considered. The initial conditions of the system were chosen as pure and mixed states, while the dynamical decoupling has been achieved by means of continuous fields. The effects of the temperature on the shielding of quantum discord is also studied. It is shown that although the quantum discord for particular initial states may be perfectly preserved over some finite time window in the absence of any protective field, the effectiveness of the dynamical decoupling with continuous fields depends essentially on the timescale required to preserve quantum discord. It is also shown that for these particular initial states the time for which the shielding of the quantum discord becomes effective decreases as the temperature increases.