Entanglement versus Quantum Discord in Two Coupled Double Quantum Dots

TL;DR

This study compares the robustness of quantum discord and entanglement in two coupled double quantum dots under dissipation, revealing quantum discord's greater resilience and potential persistence at higher temperatures.

Contribution

It provides a detailed analysis of quantum correlations dynamics in coupled quantum dots, highlighting the differential effects of dissipation on quantum discord and entanglement.

Findings

Quantum discord is more resistant to dissipation than entanglement.

Quantum discord can remain finite at higher temperatures.

The nature of the oscillator bath influences quantum correlation dynamics.

Abstract

We study the dynamics of quantum correlations of two coupled double quantum dots containing two excess electrons. The dissipation is included through the contact with an oscillator bath. We solve the Redfield master equation in order to determine the dynamics of the quantum discord and the entanglement of formation. Based on our results, we find that the quantum discord is more resistant to dissipation than the entanglement of formation for such a system. We observe that this characteristic is related to whether the oscillator bath is common to both qubits or not and to the form of the interaction Hamiltonian. Moreover, our results show that the quantum discord might be finite even for higher temperatures in the asymptotic limit.