Quantum coherence versus quantum discord in two coupled semiconductor double-dot molecules via a transmission line resonator

TL;DR

This paper investigates how quantum coherence and quantum discord evolve in two coupled semiconductor double-dot molecules mediated by a transmission line resonator, highlighting their different robustness and dynamics under dissipation.

Contribution

It provides a detailed analysis of the dynamics of quantum coherence and discord in a coupled semiconductor system, revealing their distinct behaviors and the influence of dephasing processes.

Findings

Quantum discord is more robust than entanglement against sudden death.

Dephasing can cause revival and decay of coherence and discord without entanglement.

The dynamics depend on initial states and are related to individual qubit coherences.

Abstract

We study the dynamics of quantum coherence and quantum correlations in two semiconductor double-dot molecules separated by a distance and indirectly coupled via a transmission line resonator. Dominant dissipation processes are considered. The numerical results show the sudden death of entanglement and the robustness of quantum discord to sudden death. Furthermore, the results indicate the dephasing processes in our model can lead in the revival and decay of coherence and discord with the absence of entanglement for certain initial states. By observing the dynamics of coherence versus discord for different initial states, we find that the similarities and differences of coherence and discord are not only related to the dependance of discord on optimizing the measurement set, but more importantly to the coherences in individual qubits which are captured by the adopted coherence measure.